BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Marta Marchese (Queen's University Belfast) DTSTART:20201007T130000Z DTEND:20201007T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/1 DESCRIPTION:Title: Hypothesis testing for fundamental physics\nby Marta Ma rchese (Queen's University Belfast) as part of UniKORN seminars\n\n\nAbstr act\nQuantum hypothesis testing\, \nfirst introduced for quantum state dis crimination\, has found interesting applications in quantum channels and d ynamics. Here\, we employ a variant of the test to ascertain if an optomec hanical system is subject to a possibly unknown decoherence mechanism. In particular\, our goal is to see if using quantum resources provides an adv antage in channel discrimination. Our system is made of two cavities\, one equipped with a movable mirror\, initially pumped with only coherent ligh t until reaching a steady-state configuration. At the beginning of the pro tocol\, we can additionally pump the cavities with an extra two-mode light chosen in an appropriate state. Two cases are examined\, according to the choice of the noise and output measurements: i) classical scenario\, in w hich we use two independent thermal modes and we perform local measurement s\; ii) quantum scenario\, in which we inject the cavities with two-mode s queezed light and we measure EPR-like quadratures. A standard $\\chi^2$-te st is conducted to test the two possible hypotheses on the dynamics\, name ly the presence or absence of the unknown decoherence mechanism\, that we chose to be of the continuous spontaneous localization (CSL) type. We show how two-mode squeezing appears to offer a dynamical advantage in the chan nel discrimination.\n\nThis talk is chaired and curated by Sofia Qvarfort. \n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin A. Stickler (University of Duisburg-Essen) DTSTART:20201021T130000Z DTEND:20201021T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/2 DESCRIPTION:Title: Quantum rotations in levitated optomechanics\nby Benjam in A. Stickler (University of Duisburg-Essen) as part of UniKORN seminars\ n\n\nAbstract\nThe non-linearity and anharmonicity of rigid body rotations gives rise to pronounced quantum interference effects with no analogue in the body's centre-of-mass motion. This talk will briefly review two such effects\, orientational quantum revivals [1] and the quantum tennis racket effect [2]\, and discuss how elliptic coherent scattering cooling [3] ope ns the door to rotational quantum experiments with nanoscale particles. I will also report on our recent study of controlling the rotational motion of charged nanoparticles in electric quadrupole traps [4].\n\n[1] Stickler \, Papendell\, Kuhn\, Millen\, Arndt\, and Hornberger\, New J. Phys. 20\, 122001 (2018).
\n[2] Ma\, Khosla\, Stickler\, and Kim\, Phys. Rev. Lett . 125\, 053604 (2020).
\n[3] Schäfer\, Rudolph\, Hornberger\, and Stic kler\, arXiv: 2006.04090 (2020).
\n[4] Martinetz\, Hornberger\, Millen\ , Kim\, and Stickler\, arXiv: 2005.14006 (2020).\n\nChaired by Sofia Qvarf ort.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Giles Hammond (University of Glasgow) DTSTART:20201028T140000Z DTEND:20201028T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/3 DESCRIPTION:Title: Gravitational Wave Detection\nby Giles Hammond (Univers ity of Glasgow) as part of UniKORN seminars\n\n\nAbstract\nThe Laser Inter ferometer Gravitational Wave observatory comprises two detectors located i n Hanford\, WA and Livinsgton LA. These detectors are 4km long Fabry-Perot Michelson interferometers and the most sensitive length measuring devices in the world. They are able to sense a change equivalent to 1/1000th the diameter of a proton over their 4km baseline. The interferometers utilise a 1064nm Nd-YAG laser to illuminate the cavity mirrors. The mirrors are op erated as free test masses\, requiring multiple stage pendulum suspensions and inertial seismic isolation to ensure that seismic noise does not limi t the detector sensitivity. The final stage of the suspension is fabricate d entirely from fused silica to ensure that thermal noise does not limit t heir sensitivity.\n\nIn this talk I will describe the technology developme nt necessary to realise the LIGO detectors\, and also describe the broad r ange of gravitational wave signals that have been observed during observin g runs 1-3. I will provide some insight into the astrophysics which can be gained from these “dark systems”\, only observable by listening to th e Universe\, and provide an outlook on future detectors which could operat e underground and at low temperature.\n\nThis talk will be chaired by Prof Sheila Rowan.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Hannah McAleese (Queen's University Belfast) DTSTART:20201104T140000Z DTEND:20201104T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/4 DESCRIPTION:Title: Macroscopic quantumness of optically conditioned mechanical systems\nby Hannah McAleese (Queen's University Belfast) as part of U niKORN seminars\n\n\nAbstract\nIn optomechanical systems\, conditional mea surements on the optical mode can be used to engineer states of the mechan ical mode. In this talk\, I will discuss the effect that measurement setti ngs have on the macroscopic quantumness of the mechanical mode. The measur e used is based on phase-space methods (Phys. Rev. Lett. 106\, 220401 (201 1)). The aim of the project is to find protocols which optimise mechanical macroscopicity. Additionally\, I evaluate the effect of losses for the ca se of an open cavity and analyze the impact on the features of the Wigner function of the mechanical state.\n\nChaired by Muddassar Rashid.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Montserrat Calleja (Micro and Nanotechnology Institute at CSIC) DTSTART:20201118T140000Z DTEND:20201118T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/5 DESCRIPTION:Title: Biosensors based on optonanomechanical systems\nby Mont serrat Calleja (Micro and Nanotechnology Institute at CSIC) as part of Uni KORN seminars\n\n\nAbstract\nI will present work performed in collaboratio n with Alberto Martín-Pérez\, Sergio García-López\, Marina L Yubero\, Adrián Sanz\, Javier E Escobar\, Juan Molina\, Oscar Malvar\, Priscila M Kosaka\, Daniel Ramos\, Eduardo Gil-Santos\, Jose J Ruz\, Álvaro San Paul o\, Javier Tamayo from the Bionanomechanics group at Instituto de Micro y Nanotecnología\, IMN-CNM (CSIC).\nWe will be discussing the application o f optomechanics to biology and biomedicine\, as well as how strategies ins pired by these phenomena can be applied to microscale devices for cancer c ell characterization\, for the detection of attogram per mililliter concen trations of protein biomarkers in the exploration of the deep plasma prote ome and for the identification of pathogens through their intrinsic mechan ical properties. \n\n[1] Biosensors based on nanomechanical systems\, J Ta mayo at al\, Chemical Society Reviews 42 (3)\, 1287 (2013)\n[2]Mass and st iffness spectrometry of nanoparticles and whole intact bacteria by multimo de nanomechanical resonators\nO Malvar\, JJ Ruz\, PM Kosaka\, CM Domíngue z\, E Gil-Santos\, M Calleja\, J Tamayo\, Nature communications 7\, 13452 (2016)\n[3]Silicon nanowires: where mechanics and optics meet at the nanos cale\, D Ramos\, E Gil-Santos\, O Malvar\, JM Llorens\, V Pini\, A San Pau lo\, M Calleja\, J Tamayo\, Scientific reports 3\, 3445 (2013)\n[4] Optome chanics with silicon nanowires by harnessing confined electromagnetic mode s\, D Ramos\, E Gil-Santos\, V Pini\, JM Llorens\, M Fernández-Regúlez\, A San Paulo\, M Calleja\, J Tamayo\, Nano letters 12 (2)\, 932-937 (2012) \n[5]Mechano-optical analysis of single cells with transparent microcapill ary resonators\, A Martín-Pérez\, D Ramos\, E Gil-Santos\, S García-Ló pez\, ML Yubero\, PM Kosaka\, A San Paulo\, J Tamayo\, M Calleja\, ACS sen sors 4 (12)\, 3325-3332\, 2019\n [6]Detection of cancer biomarkers in seru m using a hybrid mechanical and optoplasmonic nanosensor\, PM Kosaka\, V P ini\, JJ Ruz\, RA Da Silva\, MU González\, D Ramos\, M Calleja\, J Tamayo \, Nature nanotechnology 9 (12)\, 1047 (2014)\n [7]Optomechanical devices for deep plasma cancer proteomics\, PM Kosaka\, M Calleja\, J Tamayo\, Sem inars in cancer biology 52\, 26-38 (2018)\n [8] Gil-Santos\, E.\, Ruz\, J. J.\, Malvar\, O. et al. Optomechanical detection of vibration modes of a s ingle bacterium. Nat. Nanotechnol. 15\, 469–474 (2020). https://doi.org/ 10.1038/s41565-020-0672-y\n [9] Juan Molina\, Daniel Ramos\, Eduardo Gil-S antos\, Javier E. Escobar\, José J. Ruz\, Javier Tamayo\, Álvaro San Pau lo\, and Montserrat Calleja. Optical Transduction for Vertical Nanowire Re sonators. Nano Letters 2020 20 (4)\, 2359-2369. DOI: 10.1021/acs.nanolett. 9b04909\n\nChaired by Alexandra Olaya-Castro\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Jack Clarke (Imperial College London) DTSTART:20201125T140000Z DTEND:20201125T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/6 DESCRIPTION:Title: Creating quantum states of mechanical motion via pulsed opt omechanics\nby Jack Clarke (Imperial College London) as part of UniKOR N seminars\n\n\nAbstract\nCavity quantum optomechanics utilizes the radiat ion-pressure interaction between light and a moveable mechanical object in side a cavity for applied and fundamental physics. When combined with the tools of quantum optics\, optomechanics provides a route for engineering n on-classical states of motion in a more macroscopic regime. We explore the pulsed regime of cavity quantum optomechanics\, which utilizes pulses of light much shorter than a mechanical period\, for mechanical quantum state engineering applications. In particular\, we propose protocols for prepar ing mechanical superposition states [1] and entanglement between two massi ve oscillators [2]. \n\n[1] Jack Clarke and Michael R Vanner\, Quantum Sci . Technol. 4\, 014003 (2019)\n\n[2] Jack Clarke et al.\, New J. Phys. 22\, 063001 (2020)\n\nChaired by Markus Rademacher.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Antonio Pontin (University College London) DTSTART:20201202T140000Z DTEND:20201202T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/7 DESCRIPTION:Title: Quadratic optomechanical cooling of a cavity-levitated nano sphere.\nby Antonio Pontin (University College London) as part of UniK ORN seminars\n\n\nAbstract\nThe optomechanics field has shown tremendous a dvancements in the last couples of decades\, making an impact in both appl ications and foundational physics. Recently\, a new platform has been gath ering momentum. This is the field of levitated optomechanics where a nanop article can be trapped and manipulated in isolation from the environment b y optical\, magnetic or electric fields.\n\nIn this talk I will present ou r recent results based on the levitation of a highly charged silica nanopa rticle in a hybrid potential composed of a linear Paul trap and the standi ng wave of a high finesse cavity. With this system we were able to demonst rate cooling of the particle motion exclusively due to a coupling to the l ight which is quadratic in displacement. This is the first demonstration o f a dynamic dominated by such coupling across all optomechanical systems.\ n\nChaired by Muddassar Rashid.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Gabriel Hetet (Laboratoire de Physique de l'ENS) DTSTART:20201209T140000Z DTEND:20201209T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/8 DESCRIPTION:Title: Spin-mechanics with levitating diamonds\nby Gabriel Het et (Laboratoire de Physique de l'ENS) as part of UniKORN seminars\n\n\nAbs tract\nObserving and controlling macroscopic quantum systems has long been a driving force in research on quantum physics. The angular degrees of fr eedom of levitating diamonds coupled to embedded NV centers offer bright p rospects towards this purpose. \n\nIn this talk I will present our recent results in this direction : our observations of spin-dependent torque and spin-cooling of the diamond angular motion as well as our mechanical detec tion of dipolar interactions.\n\nChaired by James Millen.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Markus Aspelmeyer (University of Vienna) DTSTART:20200714T130000Z DTEND:20200714T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/10 DESCRIPTION:Title: Quantum optical control of levitated solids: a fresh persp ectives on the gravity-quantum interface\nby Markus Aspelmeyer (Univer sity of Vienna) as part of UniKORN seminars\n\n\nAbstract\nThe increasing level of control over motional quantum states of massive\, solid-state mec hanical devices opens the door to an hitherto unexplored parameter regime of macroscopic quantum physics. I will report on our recent progress towar ds controlling levitated solids in the quantum regime. I will discuss the prospects of using these systems for fundamental tests of physics\, includ ing the interface between quantum and gravitational physics.\n\nRecorded t alk available upon email request.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Marko Toroš (University College London) DTSTART:20200722T130000Z DTEND:20200722T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/11 DESCRIPTION:Title: Quantum sensing and cooling in three-dimensional levitated cavity optomechanics\nby Marko Toroš (University College London) as part of UniKORN seminars\n\n\nAbstract\nA recent experimental breakthrough has propelled levitated optomechanics into the quantum domain [1]. The ne w coherent scattering (CS) setup has the capability to prepare highly non- classical states for nano-sized objects\, opening the possibility to explo re unprobed quantum mechanical regimes. We will briefly review the main fe atures of the CS setup and highlight some of its novel 3D aspects such as the hybridization of the mechanical modes and the backaction effects [2]. We will conclude by a few remarks on possible applications such as testing gravitational effects in Quantum mechanics [3].\n\n[1] Delić U\, Reisenb auer M\, Dare K\, Grass D\, Vuletić V\, Kiesel N\, Aspelmeyer M. Cooling of a levitated nanoparticle to the motional quantum ground state. Science. 2020 Feb 21\;367(6480):892-5.\n\n[2] Toroš\, M. and Monteiro\, T.S.\, 20 20. Quantum sensing and cooling in three-dimensional levitated cavity opto mechanics. Physical Review Research\, 2(2)\, p.023228.\n\n[3] Bose\, S.\, Mazumdar\, A.\, Morley\, G.W.\, Ulbricht\, H.\, Toroš\, M.\, Paternostro\ , M.\, Geraci\, A.A.\, Barker\, P.F.\, Kim\, M.S. and Milburn\, G.\, 2017. Spin entanglement witness for quantum gravity. Phys. Rev. Lett. 119(24)\, p.240401.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Georg Enzian (University of Copenhagen) DTSTART:20200729T130000Z DTEND:20200729T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/12 DESCRIPTION:Title: Brillouin cavity optomechanics with whispering-gallery mic roresonators\nby Georg Enzian (University of Copenhagen) as part of Un iKORN seminars\n\n\nAbstract\nCavity quantum optomechanics uses fields of light to generate and study quantum states of motion of macroscopic mechan ical resonators and is one of the newest and most rapidly growing areas of quantum optics. Excitingly\, the field pursues several different experime ntal directions including Fabry-Perot cavities with movable mirrors\, levi tated optomechanical systems\, and other nano-optical implementations\, ea ch having their own advantages and disadvantages. In this talk\, a new dir ection – Brillouin optomechanics – will be discussed\, which unites se veral favourable properties including very high mechanical frequencies (> 10 GHz)\, very low optical loss and absorption\, and back-scatter operatio n to allow the signal to be easily separated from the pump. Using a silica micro-resonator\, we have experimentally observed Brillouin optomechanica l strong coupling between the optical cavity field and these high-frequenc y mechanical vibrations [Optica 6\, 7 (2019)]. Additionally\, I will discu ss a recent experiment performing single-phonon addition and subtraction t o a mechanical thermal state of the acoustic whispering-gallery wave [arXi v:2006.11599]. This research opens a rich avenue for further studies that test the very foundations of quantum mechanics and the development of powe rful new quantum technologies.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Alessio Belenchia (Queen's University Belfast) DTSTART:20200805T130000Z DTEND:20200805T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/13 DESCRIPTION:Title: Optomechanics meets Thermodynamics: Experimental assessmen t of entropy production in a continuously measured mechanical resonator\nby Alessio Belenchia (Queen's University Belfast) as part of UniKORN se minars\n\n\nAbstract\nThe information on a quantum process acquired throug h measurements plays a crucial role in the determination of its non-equili brium thermodynamic properties. In this talk\, we report on the experiment al inference of the stochastic entropy production rate for a continuously monitored mesoscopic quantum system. We consider an optomechanical system subjected to continuous displacement Gaussian measurements and characteris e the entropy production rate of the individual trajectories followed by t he system in its stochastic dynamics. Owing to the specific regime of our experiment\, we are able to single out the informational contribution to t he entropy production arising from conditioning the state on the measureme nt outcomes. This experiment embodies a significant step towards the demon stration of full-scale control of fundamental thermodynamic processes at t he mesoscopic quantum scale.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Laure Mercier de Lépinay (Aalto University) DTSTART:20200812T130000Z DTEND:20200812T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/14 DESCRIPTION:Title: Optomechanical nonreciprocal refrigerator\nby Laure Me rcier de Lépinay (Aalto University) as part of UniKORN seminars\n\n\nAbst ract\nCavity optomechanics has successfully proposed inventive cooling tec hniques for mechanical oscillators\, allowing to bring phononic occupation s of macroscopic motion modes below unity. On the other hand\, in the past few years\, mechanically-mediated\, nonreciprocal coupling of electromagn etic cavities has been extensively studied as a means to engineer directio nal propagation of signal and noise. Interestingly\, the directional propa gation of noise between mechanical oscillators can be expected to propose a novel cooling mechanism based on nonreciprocal coupling of mechanical os cillators. Ref [1] published in 2019 gave an experimental study of the imp act of nonreciprocal coupling of a pair of membrane modes on their phononi c occupancies. We propose interpretations of the observed signatures\, and show that different simultaneous cooling mechanisms coexist. We show that one among these can indeed be identified as nonreciprocal cooling. Its im pact must however be carefully distinguished from the other cooling mechan isms’\, for which we propose an experimental method. The method is carri ed out experimentally on a pair of drum resonators in optomechanical coupl ing with a microwave cavity. We discuss the nature of the stationary state generated in such nonreciprocally-coupled systems\, and show that a quant um limit exists to the novel nonreciprocal cooling mechanism\, which emerg es in our experimental setup thanks to operation at low phonon numbers. Ob taining reduced phononic occupancies requires work from the experimentalis t to bring the system out of equiblibrium\, which makes the system analogo us to a refrigerator functioning at low phonon numbers.\n\n[1] H. Xu\, L. Jiang\, A. A. Clerk and J. G. E. Harris\, “Nonreciprocal control and coo ling of phonon modes in an optomechanical system”\, Nature\, vol. 568 p. 65\, 2019\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Natalia Ares (University of Oxford) DTSTART:20200819T130000Z DTEND:20200819T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/15 DESCRIPTION:Title: Circuit optomechanics for thermodynamics at the nanoscale< /a>\nby Natalia Ares (University of Oxford) as part of UniKORN seminars\n\ n\nAbstract\nThe laws of thermodynamics are physics’ most solid pillar\, governing everything from black holes to the evolution of life. Rapid bre akthroughs in optomechanics are now presenting us with the opportunity to test these laws in a completely new realm\, where fluctuations are importa nt and quantum effects might arise. I will show you how we can explore the rmodynamics in this limit by probing the displacement of a nanomechanical resonator. I will discuss the potential of optomechanical systems to pave the way for experiments on quantum information thermodynamics\, in particu lar\, for revealing the thermodynamic costs of quantum operations.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Daniel Goldwater (University of Nottingham) DTSTART:20200902T130000Z DTEND:20200902T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/16 DESCRIPTION:Title: A Quantum Spectrometer for Arbitrary Noise\nby Daniel Goldwater (University of Nottingham) as part of UniKORN seminars\n\n\nAbst ract\nThis talk will report on and explain a recent proposal [PRL\, 2019] for a quantum spectrometer. This equates to a technique for recovering the spectrum of a non-Markovian bosonic bath coupled to a harmonic oscillator \; a technique which is valid under the conditions that the environment is large and hot compared to the oscillator\, and that its temporal autocorr elation functions are symmetric with respect to time translation and refle ction (fairly minimal criteria). Since our proposal doesn’t rely on dyna mically decoupling qubits\, and rather works with any quantum harmonic osc illator\, it could be used to probe collapse models with non-white noises. The talk will explain the spectrometer itself\, and expand on possible ap plications in quantum foundations.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Anna Pearson (University of Oxford) DTSTART:20200909T130000Z DTEND:20200909T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/17 DESCRIPTION:Title: Measuring the thermodynamic cost of timekeeping with a rad io-frequency optomechanical system.\nby Anna Pearson (University of Ox ford) as part of UniKORN seminars\n\n\nAbstract\nThis talk will discuss a radio-frequency optomechanical experiment that has explored the thermodyna mic cost of timekeeping (arXiv: 2006.08670). The evolution of nature towar ds higher entropy states is used by clocks to quantify the passage of time . A minimal model for an autonomous quantum clock in the quantum realm has shown that within a certain regime an increase in entropy linearly increa ses the accuracy of quantum clocks. (Phys. Rev. X 7\, 031022 (2017)) We d erive a theoretical bound for our classical clock\, which consists of a si licon nitride membrane capacitively coupled to a radio-frequency cavity (S ci. Rep. 10\, 1654 (2020)) . The bound shows that the accuracy of the clas sical clock is also proportional to the entropy created per tick\, but wit h a different proportionality constant to the quantum case. Experimentall y we find that there is a linear relationship between the clock’s accura cy and its entropy production\, and that our experiment operates within an order of magnitude of the theoretical bound.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/17/ END:VEVENT BEGIN:VEVENT SUMMARY:Jack Harris (Yale University) DTSTART:20200916T130000Z DTEND:20200916T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/18 DESCRIPTION:Title: Single phonon quantum acoustics with superfluid helium \nby Jack Harris (Yale University) as part of UniKORN seminars\n\n\nAbstra ct\nQuantum effects in acoustic degrees of freedom offer exciting opportun ities in sensing\, control\, and information processing\, as well as in st udies of fundamental physics. To date\, much progress in this field has be en made with systems whose dynamics is essentially linear (this includes t he realization of acoustic oscillators in their ground state or in squeeze d states\, and the observation of entanglement among acoustic and electrom agnetic modes). However\, these systems’ linearity precludes access to “stronger” quantum effects that would offer true performance enhanceme nt and tests of quantum mechanics in new regimes. One route to realizing n onlinear quantum acoustics is based on the back-action of single photon de tectors. In this talk\, I will describe our use of this approach to detect and control individual phonons in a nanogram-scale body of superfluid hel ium. I will also described the future prospects of superfluid-based quantu m acoustic systems.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/18/ END:VEVENT BEGIN:VEVENT SUMMARY:Yue Ma (Imperial College London) DTSTART:20200923T130000Z DTEND:20200923T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/19 DESCRIPTION:Title: Quantum Persistent Tennis Racket Dynamics of Nanorotors\nby Yue Ma (Imperial College London) as part of UniKORN seminars\n\n\nAb stract\nClassical tennis racket effect refers to the instability of mid-ax is rotation of an asymmetric rigid rotor. The flipping period of the mid-a xis orientation sensitively depends on the initial energy. Once averaged o ver a thermal ensemble\, the flipping rapidly decays. However\, the situat ion is completely different in the quantum regime. Classically forbidden t unnelling and reflection near the separatrix redistribute the energy eigen values\, therefore changing the distribution of mid-axis flipping frequenc ies. In a rapidly spinning quantum asymmetric rotor\, the mid-axis flippin g persists much longer than the classical case\, even when millions of ang ular momentum states are occupied. The persistent flipping is expected to be observable in nanoparticles or molecules when combining state-of-the-ar t technologies. [10.1103/PhysRevLett.125.053604]\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin A. Stickler (University of Duisburg-Essen) DTSTART:20210111T100000Z DTEND:20210111T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/20 DESCRIPTION:Title: Lecture series: Decoherence in Macroscopic Quantum Systems \nby Benjamin A. Stickler (University of Duisburg-Essen) as part of Un iKORN seminars\n\n\nAbstract\nSession 1: Introduction & Basics of Open Qua ntum Systems\n\nSession topics:\n\n \nLecture series abstract:\n\nWhile the Schrödinger equation describes th e dynamics of isolated quantum systems\, real-world systems are always in contact with ambient environments. This leads to thermalisation as well as to decoherence\, which can explain the emergence of classical behaviour f or objects of increasing size and complexity. This short lecture series wi ll provide the general framework to quantitatively describe the dynamics o f open quantum systems and apply it to several practically relevant situat ions. Amongst others\, we will explore the role of decoherence in macrosco pic matter-wave interference experiments and discuss the influence of the environment in quantum optomechanics.\n\nA recorded version of the lecture series is available upon email request.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin A. Stickler (University of Duisburg-Essen) DTSTART:20210112T100000Z DTEND:20210112T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/21 DESCRIPTION:Title: Lecture series: Decoherence in Macroscopic Quantum Systems \nby Benjamin A. Stickler (University of Duisburg-Essen) as part of Un iKORN seminars\n\n\nAbstract\nSession 2: The Monitoring approach\n\nSessio n topics:\n\ n\n\nLecture series abstract:\n\nWhile the Schrödinger equation describes the dynamics of isolated quantum systems\, real-world systems are always in contact with ambient environments. This leads to thermalisation as well as to decoherence\, which can explain the emergence of classical behaviou r for objects of increasing size and complexity. This short lecture series will provide the general framework to quantitatively describe the dynamic s of open quantum systems and apply it to several practically relevant sit uations. Amongst others\, we will explore the role of decoherence in macro scopic matter-wave interference experiments and discuss the influence of t he environment in quantum optomechanics.\n\nA recorded version of the lect ure series is available upon em ail request.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/21/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin A. Stickler (University of Duisburg-Essen) DTSTART:20210114T100000Z DTEND:20210114T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/22 DESCRIPTION:Title: Lecture series: Decoherence in Macroscopic Quantum Systems \nby Benjamin A. Stickler (University of Duisburg-Essen) as part of Un iKORN seminars\n\n\nAbstract\nSession 4: Macroscopic tests of quantum phys ics\n\nSession topics:\n\n\nLecture series abstract:\n\nWhile the Schrödinger equa tion describes the dynamics of isolated quantum systems\, real-world syste ms are always in contact with ambient environments. This leads to thermali sation as well as to decoherence\, which can explain the emergence of clas sical behaviour for objects of increasing size and complexity. This short lecture series will provide the general framework to quantitatively descri be the dynamics of open quantum systems and apply it to several practicall y relevant situations. Amongst others\, we will explore the role of decohe rence in macroscopic matter-wave interference experiments and discuss the influence of the environment in quantum optomechanics.\n\nA recorded versi on of the lecture series is available upon email request.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/22/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin A. Stickler (University of Duisburg-Essen) DTSTART:20210113T100000Z DTEND:20210113T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/23 DESCRIPTION:Title: Lecture series: Decoherence in Macroscopic Quantum Systems \nby Benjamin A. Stickler (University of Duisburg-Essen) as part of Un iKORN seminars\n\n\nAbstract\nSession 3: Decoherence and thermalisation\n\ nSession topics:\n\n\n\nLec ture series abstract:\n\nWhile the Schrödinger equation describes the dyn amics of isolated quantum systems\, real-world systems are always in conta ct with ambient environments. This leads to thermalisation as well as to d ecoherence\, which can explain the emergence of classical behaviour for ob jects of increasing size and complexity. This short lecture series will pr ovide the general framework to quantitatively describe the dynamics of ope n quantum systems and apply it to several practically relevant situations. Amongst others\, we will explore the role of decoherence in macroscopic m atter-wave interference experiments and discuss the influence of the envir onment in quantum optomechanics.\n\nA recorded version of the lecture seri es is available upon email requ est.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/23/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin A. Stickler (University of Duisburg-Essen) DTSTART:20210115T100000Z DTEND:20210115T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/24 DESCRIPTION:Title: Lecture series: Decoherence in Macroscopic Quantum Systems \nby Benjamin A. Stickler (University of Duisburg-Essen) as part of Un iKORN seminars\n\n\nAbstract\nSession 5: Advanced topics\n\nSession topics :\n\n\n\nLecture series abstract:\n\nWhile the Schrödinger equation describes the dynamics of isolated quantum syst ems\, real-world systems are always in contact with ambient environments. This leads to thermalisation as well as to decoherence\, which can explain the emergence of classical behaviour for objects of increasing size and c omplexity. This short lecture series will provide the general framework to quantitatively describe the dynamics of open quantum systems and apply it to several practically relevant situations. Amongst others\, we will expl ore the role of decoherence in macroscopic matter-wave interference experi ments and discuss the influence of the environment in quantum optomechanic s.\n\nA recorded version of the lecture series is available upon email request.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/24/ END:VEVENT BEGIN:VEVENT SUMMARY:Mauro Paternostro (Queen's University Belfast) DTSTART:20210127T140000Z DTEND:20210127T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/25 DESCRIPTION:Title: Seeing without looking: an optomechanical quest for quantu m gravity\nby Mauro Paternostro (Queen's University Belfast) as part o f UniKORN seminars\n\n\nAbstract\nI will provide a general overview of the underlying principles behind recent proposals for the exploration of the potential quantum nature of gravity through optomechanical settings. I wil l find illustrate a simple information-theoretic argument behind recent en tanglement gain-based proposals and then discuss the implications for expe rimental endeavours based on (hybrid) optomechanics\n\nChaired by Prof Sou gato Bose\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/25/ END:VEVENT BEGIN:VEVENT SUMMARY:Igor Pikovski (University of Stockholm) DTSTART:20210203T140000Z DTEND:20210203T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/26 DESCRIPTION:Title: Optomechanics as a versatile tool to probe classical and q uantum gravity.\nby Igor Pikovski (University of Stockholm) as part of UniKORN seminars\n\n\nAbstract\nThe advance of optomechanical systems has helped establish a new line of research on the interface between quantum physics and gravity at low energies. In this talk\, I will discuss some of the proposed experiments in this field\, ranging from tests of quantum gr avity models to gravitational wave detection with novel opto-mechanical se tups. After giving a brief overview\, I will focus on proposals to probe q uantum gravity models with a modified commutation relation that are within reach of optomechanical experiments.\n\nChaired by Prof Myungshik Kim\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/26/ END:VEVENT BEGIN:VEVENT SUMMARY:Ryan Marshman\, Sandro Donadi\, Matteo Carlesso DTSTART:20210210T140000Z DTEND:20210210T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/27 DESCRIPTION:Title: Quantum Nature of Linearised Gravity\, the Diósi-Penrose model & Challenges in table-top experiments\nby Ryan Marshman\, Sandro Donadi\, Matteo Carlesso as part of UniKORN seminars\n\n\nAbstract\n1st t alk: "Large Mass Interferometry for Witnessing the Quantum Nature of Linea rised Gravity"\nSpeaker: Ryan Marshman\n\nAbstract: Recent work has opened up the prospect that conclusive evidence could be obtained for the quantu m nature of gravity. Specifically\, by witnessing the gravitationally gene rated entanglement which may form between two large mass interferometers. In this seminar I will discuss importance of the assumption of locality of physical interactions\, and the concomitant necessity of propagation of a n entity (in this case\, off-shell quanta - virtual gravitons) between two non-relativistic test masses in unveiling the quantum nature of linearise d gravity through a laboratory experiment. In doing so I seek to provide a n intuitive understanding behind the underlying physics and implications o f a successful experiment evidencing gravitationally mediated entanglement . \n\n-------------------------------------------------------------------- ----------------------------\n\n2nd talk: "The Diósi-Penrose model under X-rays"\nSpeaker: Sandro Donadi\n\nAbstract: According to the Diósi-Penro se (DP) model\, quantum superpositions in space are not stable and gravity plays a role in the spontaneous decay of these superpositions in localize d states. The larger is the mass of the system\, the shorter is the time t aken by the superposition to collapse. \nA direct test of this idea requir es the creation of a spatial superposition which is kept stable for times longer than the one required to the gravity-related collapse to become eff ective. Interesting proposals have been put forward in this direction\, bu t they are still hard to be achieved. \n\nIn this seminar\, I will discuss a different way to test the DP model. This test is based on the fact that the gravity-related collapse predicted by the DP model also induces a Bro wnian-like motion in space of the system. For charged particles\, this Bro wnian-like motion leads to an emission of photons\, which is faint but det ectable. \nWe computed the photon emission rate predicted by the DP model and compared it with the data from a dedicated experiment performed in the ultra-low background radioactivity environment at the Gran Sasso Laborato ries. Our results rule out the parameter-free version of the model and set a strong bound on its parameter-dependent version.\n\n------------------- -------------------------------------------------------------------------- ---\n\n3rd talk: "Witnessing the Quantum Nature of Linearised Gravity: Cha llenges in table-top experiments"\nSpeaker: Matteo Carlesso\n\nAbstract: T he possible observation of a clear quantum signature of gravity is a chall enging problem. In this talk\, I will give an overview of the challenges r ecent table-top experimental proposals must face. I will then compare thei r status to the required working conditions to witness possible quantum fe atures of gravity. I will conclude briefly presenting a different scheme w hich tackles the problem from another and\, hopefully\, more feasible\, pe rspective.\n\nChaired by Marko Toros\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/27/ END:VEVENT BEGIN:VEVENT SUMMARY:Angelo Bassi\, Miles Blencowe\, Caslav Brukner\, Ivette Fuentes\, Andrew Geraci and Gary Steele DTSTART:20210217T140000Z DTEND:20210217T153000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/28 DESCRIPTION:Title: Panel discussion "Optomechanical interfaces of quantum mec hanics and gravity"\nby Angelo Bassi\, Miles Blencowe\, Caslav Brukner \, Ivette Fuentes\, Andrew Geraci and Gary Steele as part of UniKORN semin ars\n\n\nAbstract\nWe are delighted to present our panel members Angelo Ba ssi\, Miles Blencowe\, Caslav Brukner\, Ivette Fuentes\, Andrew Geraci and Gary Steele. The panel discussion will focus on the following three quest ions:\n\n1. In what experiments might we observe an interplay between quan tum mechanical and gravitational effects?\n\n2. What theoretical advances are needed to describe this interplay?\n\n3. What parameter regimes are th e most interesting for these experiments? \n\nThe discussion will begin wi th short a introductions by each of the panel members on their views regar ding the interplay between quantum mechanics and gravity\, followed by a d iscussion of the three questions listed above. After that\, the floor will be open to questions from the audience.\n\nChaired by Sofia Qvarfort and Hendriik Ulbricht.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/28/ END:VEVENT BEGIN:VEVENT SUMMARY:Warwick Bowen (School of Maths and Physics\, University of Queensl and) DTSTART:20210303T100000Z DTEND:20210303T110000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/29 DESCRIPTION:Title: Sensing beyond the conventional limits\nby Warwick Bow en (School of Maths and Physics\, University of Queensland) as part of Uni KORN seminars\n\n\nAbstract\nIt has been known for over a century that\, i n quantum physics\, even the act of looking can have dramatic consequences . For instance\, it kills the cat in Schrödinger’s famous thought exper iment. However\, it has proved extremely difficult to observe such effects in practice\, except for the smallest atom-scale objects\, let alone to u se them as a tool to enhance technologies. \n \nOver the past decade\, how ever\, advances in nanotechnology have allowed us to engineer devices whic h exhibit this distinctive quantum behavior [1]. These “quantum optomech anical devices” consist of a nanoscale mechanical object – for example \, a nanoparticle\, molecule or cantilever – coupled to light via radiat ion pressure\, often concentrated in a tiny optical cavity. In essence\, t hey are miniature versions of the kilometer-scale interferometers that hav e enabled the extraordinary detection of gravitational waves from distant black hole collisions (see Figure). Quite remarkably\, they can allow meas urements of motion at the sub-attometre level – more than a thousand tim es below the width of an atomic nucleus. At a fundamental level\, this all ows us to ask new questions of quantum physics for macroscopic systems con sisting of trillions of atoms. It also provides a way to build precision o ptical sensors that far outperform the current state-of-the-art. \n \nIn t his talk\, I will provide an overview of optomechanical sensors developed in my laboratory\, with a particular focus on applications in the bioscien ces. This includes quantum-enhanced probing of molecular vibrations that a llows absolute quantum advantage in microscopy [2]\; optical trapping and tracking techniques that allow speedy viscosity measurements and non-invas ive single molecule detection [3]\; and air-coupled optomechanical ultraso und transducers with sensitivity orders-of-magnitude better than the curre nt state-of-the-art [4] that could be used to listen to the sounds made by the motor molecules in single living cells or bacteria.\n \n\n1. Bowen an d Milburn\, Quantum Optomechanics\, CRC Press (2016).\n\n2. arXiv:2004.00 178 (2020).\n\n3. In print\, Nature Photonics (2021)\, arXiv:2007.03066\; also Nature Photonics 11\, 477-481 (2017)\; Nature Photonics 9\, 669-673 ( 2015)\; Nature Photonics 7\, 229-233 (2013).\n\n4. See e.g. Nature Communi cations 10\, 132 (2019).\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/29/ END:VEVENT BEGIN:VEVENT SUMMARY:Dave Moore (Yale University) DTSTART:20210310T140000Z DTEND:20210310T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/30 DESCRIPTION:Title: Searching for new physics with levitated optomechanics \nby Dave Moore (Yale University) as part of UniKORN seminars\n\n\nAbstrac t\nThe development of precise force sensors and accelerometers based on le vitated optomechanical systems is enabling searches for new fundamental in teractions in precision experiments. I will describe the optical trapping\ , control\, and readout of nanogram-scale masses in vacuum optical tweezer s\, and their applications to searches for new weakly coupled particles or forces. Recent searches for dark matter using these systems will be descr ibed\, as well as ongoing work to search for new forces that could appear at micron distances.\n\nChaired by Dr. Michael Vanner\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/30/ END:VEVENT BEGIN:VEVENT SUMMARY:Nancy Aggarwal\, Ben Wood and Peng Ju DTSTART:20210317T140000Z DTEND:20210317T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/31 DESCRIPTION:Title: Sensing: Optomechanical Squeezing\, Superposition of Nanod iamonds & An Optically Levitated Nanorotor\nby Nancy Aggarwal\, Ben Wo od and Peng Ju as part of UniKORN seminars\n\n\nAbstract\nTalk 1: Room-tem perature optomechanical squeezing by Nancy Aggarwal\n\nAbstract: Current g round-based gravitational-wave (GW) detectors are large-scale optomechanic al systems measuring displacements at the quantum limit. I will summarize the current work on the quantum measurements frontier in the LIGO collabor ation. I will also try to convince you that it is indeed possible for a ma croscopic\, room-temperature system to have low enough Brownian motion so as to exhibit measureable quantum effects like squeezing [1]. \n\n[1] $\\u rl{https://www.nature.com/articles/s41567-020-0877-x}$ and $\\url{https:// www.nature.com/articles/s41586-019-1051-4}$\n\n--------------------------- ----------------------------------------------------------------\n\nTalk 2 : Towards Macroscopic Spatial Superposition of Nanodiamonds by Ben Wood\n\ n\nAbstract: Nanodiamonds containing negatively charged nitrogen vacancy c entres (NV) have been proposed as a platform to generate macroscopic spati al quantum superpositions. These superpositions could be used as highly se nsitive gravity sensors or even to probe the quantum nature of gravity\, h owever\, experimental challenges need to be overcome to realise these prop osals. In this talk I will discuss current work on three of these challeng es. Firstly\, we have measured long\, room temperature\, spin coherence ti mes of NV in nanodiamonds produced by silicon nitride ball milling. Second ly\, we are developing a diamagnetic trap for passive neutral-nanodiamond levitation. Finally\, we propose a magnetic field structure to generate a spatial superposition in a free-fall experiment\, allowing for dynamical d ecoupling spin flips.\n\n------------------------------------------------- ------------------------------------------\n\nTalk 3: Ultrasensitive torqu e detection with an optically levitated nanorotor by Peng Ju\n\nAbstract: Torque sensors such as the torsion balance enabled the first determination of the gravitational constant by Henri Cavendish and the discovery of Cou lomb’s law. Great effort has been made to get more sensitive torque sens ors\, which are widely used in studying small-scale magnetism\, the Casimi r effect and other applications. With an optically levitated silica nanopa rticle in vacuum\, we are able to reach a record torque sensitivity of $(4 .2 \\pm 1.2) \\times 10^{-27}$ Nm Hz$^{-1/2}$ at room temperature. Moreove r\, we drive a nanoparticle to rotate at a high speed beyond 5 GHz(300 bil lion r.p.m.). Our calculations show that this system will be able to detec t the long-sought-after vacuum friction near a surface under realistic con ditions.\n\n[1] $\\url{https://www.nature.com/articles/s41565-019-0605-9}$ \n\nChaired by Maryam Nikkhou.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/31/ END:VEVENT BEGIN:VEVENT SUMMARY:Kai Bongs\, John Davis\, Gabriella Mifsud\, Clemens Schäfermeier and Douglas Paul (University of Birmingham\, University of Alberta\, Accel er8\, AttoCube and University of Glasgow) DTSTART:20210324T150000Z DTEND:20210324T163000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/32 DESCRIPTION:Title: Panel discussion: How do you build and sell an optomechani cal sensor?\nby Kai Bongs\, John Davis\, Gabriella Mifsud\, Clemens Sc häfermeier and Douglas Paul (University of Birmingham\, University of Alb erta\, Acceler8\, AttoCube and University of Glasgow) as part of UniKORN s eminars\n\n\nAbstract\nWe live in an exciting era where the commercialisat ion of various quantum technologies is quickly becoming reality. However\, there are a number of challenges beyond fundamental research that accompa ny the development and commercialisation of a product. In this panel discu ssion\, which brings together experts from industry and academia\, we ask the question: “How do you build and sell an optomechanical sensor?”. T he discussion will focus on how to identify research as suitable for comme rcialisation and building a creative and productive environment for these research outputs. We will also discuss the question of marketing and selli ng the technology.\n\nChaired by James Millen.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/32/ END:VEVENT BEGIN:VEVENT SUMMARY:Stefano Vitale (University of Trento/IstitutoNazionale di Fisica N ucleare/Agenzia Spaziale Italiana) DTSTART:20210407T130000Z DTEND:20210407T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/33 DESCRIPTION:Title: LISA Pathfinder and LISA\nby Stefano Vitale (Universit y of Trento/IstitutoNazionale di Fisica Nucleare/Agenzia Spaziale Italiana ) as part of UniKORN seminars\n\n\nAbstract\nLISA is a space-borne gravita tional wave (GW) observatory under development by the European Space Agenc y (ESA). It aims at the GW spectrum between a few tens of micro-Hz and a f raction of a Hz\, which cannot be accessed by ground-based detectors. LIS A has been preceded by a precursor mission\, LISA Pathfinder\, that has su ccessfully demonstrated the necessary space-time metrology. \nThe talk wil l review both the basic principles of LISA and the status of its developm ent\, and the objectives\, design\, operations and achievements of LISA Pathfinder.\n\nChaired by Giles Hammond.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/33/ END:VEVENT BEGIN:VEVENT SUMMARY:Rainer Kaltenbaek (Faculty of Mathematics and Physics\, University of Ljubljana) DTSTART:20210414T130000Z DTEND:20210414T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/34 DESCRIPTION:Title: Testing quantum physics in space: challenges and progress< /a>\nby Rainer Kaltenbaek (Faculty of Mathematics and Physics\, University of Ljubljana) as part of UniKORN seminars\n\n\nAbstract\nSince its incept ion in 2010\, significant progress has been made in the development of the MAQRO mission proposal to build a dedicated satellite for testing the fou ndations of quantum physics. In 2017\, the European Space Agency (ESA) cho se this as one of its New Science Ideas for future missions\, and it condu cted a detailed study at their Concurrent Design Facility (CDF) on the tec hnical feasibility of a future quantum physics platform (QPPF) based on th e MAQRO mission concept. The conclusion of the study was that such a missi on is feasible\, in principle\, but that three critical\, technical challe nges have to be met before a potential future implementation. Here\, we wi ll discuss these challenges\, recent progress\, as well as planned and on- going research activities to meet these challenges.\n\nChaired by Gavin Mo rley.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/34/ END:VEVENT BEGIN:VEVENT SUMMARY:Jasminder Sidhu\, Christian Vogt\, Stephan Tobias Seidel (Universi ty of Strathclyde\, Universität Bremen\, Airbus) DTSTART:20210421T130000Z DTEND:20210421T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/35 DESCRIPTION:Title: Photonics\, nanoparticles and cold-atoms as role models fo r space-based test with optomechanics\nby Jasminder Sidhu\, Christian Vogt\, Stephan Tobias Seidel (University of Strathclyde\, Universität Bre men\, Airbus) as part of UniKORN seminars\n\n\nAbstract\n1st talk: Satelli te-based Quantum Communications\;\nSpeaker: Jasminder Sidhu\n\nAbstract: G lobal quantum communications is important for distributed quantum informat ion processing over long-distances\, and entanglement-enabled technologies . However\, range limitations of fibre optical transmission restricts the reach of networked quantum technologies. Satellite-based quantum communica tion provides a practical and realisable route to intercontinental quantum networking\, and is rapidly being developed. In this talk\, we briefly re view these developments and highlight some of the unique challenges in spa ce-based quantum communications.\n\n-------------------------------------- ----------------------------------------------------------\n\n2nd talk: Co oled nanoparticles in a drop tower\;\nSpeaker: Christian Vogt\n\nAbstract: \nLevitated optomechanics based on levitated silica nanospheres is a promi sing tool for force measurements and observation of the quantum mechanical behavior of "large" masses. Especially the latter benefits strongly from a space environment\, as proposed in MAQRO mission.\nNevertheless\, space- based experiments rely on rigorous preparation and need as much validation of the proposed techniques as possible\, including under weightlessness c onditions. Our approach is to operate a system with parametrically cooled nanoparticles in the drop tower in Bremen\, providing 4.7 s of weightlessn ess time\, 9.3 s in catapult mode. \nBeyond demonstrating feasibility\, su ch an experiment allows for the realization of even slower nanoparticles\, increased force sensitivity\, or even "macroscopic" interference. This ta lk will discuss the various ideas for drop tower applications\, its benefi ts for ground-based experiments\, and how we can support these with our fi ndings on optically trapped neutral atoms in the drop tower.\n\n\n-------- -------------------------------------------------------------------------- --------------\n\n3rd talk: Cold Atom Interferometry in Space\;\nSpeaker: Stephan Tobias Seidel\n\nAbstract:\nCold Atom Interferometers (CAI) are qu antum sensors based on the interference of matterwaves that allow for meas urements of accelerations and rotations with a high accuracy. The realisat ion of CAIs in microgravity allows to drastically increase the free interr ogation time of the atoms in the CAI compared to measurements in gravity. This in turn\, increases the sensitivity of the measurement as it scales q uadratically with the free interrogation time.\nThis talk will briefly dis cuss the principles of CAIs\, their applications in space and the current state of microgravity demonstrations.\n\nChaired by Lisa Wörner.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/35/ END:VEVENT BEGIN:VEVENT SUMMARY:Mike Cruise\, Chris Lee\, James Endicott\, Daniel Oi (University o f Birmingham\, Space Academic Network\, Open University\, University of St rathclyde) DTSTART:20210428T130000Z DTEND:20210428T143000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/36 DESCRIPTION:Title: Panel discussion: Space-based tests with optomechanics \nby Mike Cruise\, Chris Lee\, James Endicott\, Daniel Oi (University of B irmingham\, Space Academic Network\, Open University\, University of Strat hclyde) as part of UniKORN seminars\n\n\nAbstract\nPanel discussion with t he different academic and industrial stakeholders involved in the UK’s r oadmap of space exploration and how in particular space-based tests with o ptomechanics fit into this broader context. A few of the questions we will try to answer will include: \n\n- Why should we try to do physics in spac e?\n\n- What are the advantages provided\, in the context of quantum tests in space\, by the use of small satellites? How can we exploit them as kic k-starters to advance technology?\n\n- What is the added value that would be provided by optomechanical platforms?\n\n- How can we connect optomecha nical systems in space networks?\n\nChaired by Mauro Paternostro.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/36/ END:VEVENT BEGIN:VEVENT SUMMARY:Albert Schliesser (Neils Bohr Institute) DTSTART:20210512T130000Z DTEND:20210512T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/37 DESCRIPTION:Title: Measurement-based quantum control of macroscopic motion\nby Albert Schliesser (Neils Bohr Institute) as part of UniKORN seminars \n\n\nAbstract\nOver the last 15 years\, we have seen dramatic advances in the ability to control the quantum state of nano- and micro-mechanical sy stems\, by coupling them to light or microwaves. Coherent control\, such a s laser sideband cooling\, has been used successfully to prepare low-entro py quantum states of mechanical systems. In this talk\, I will focus on a different paradigm\, namely measurement-based quantum control. \nUsing opt ical interferometry\, we monitor the motion of the membrane with attometer sensitivity. The membranes host extremely coherent mechanical resonance m odes\, shielded from the environment by a phononic crystal pattern. In thi s setting\, we directly observe the quantum back-action of the measurement process on the measured object in the form of quantum fluctuations of rad iation pressure. By trading off imprecision and back-action\, we closely a pproach the standard quantum limit (SQL) in the sensitivity to mechanical displacement. We then use the information gained through the measurement t o obtain pure mechanical quantum trajectories (conditioned the measurement record). By applying real-time feedback\, we can also prepare an uncondit ional low-entropy quantum state. Interestingly\, exploiting quantum correl ations born in the measurement process\, we can even overcome the SQL in d isplacement and force measurements. Based on the same underlying correlati ons\, we evidence entanglement in the optical output modes of the system.\ nI will conclude with a short outlook on potential applications in future quantum technologies.\n\nChaired by Peter Barker.\nRecorded talk available upon email request.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/37/ END:VEVENT BEGIN:VEVENT SUMMARY:John Teufel (NIST/Boulder) DTSTART:20210519T130000Z DTEND:20210519T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/38 DESCRIPTION:Title: Listening to the Sound of Entanglement\nby John Teufel (NIST/Boulder) as part of UniKORN seminars\n\n\nAbstract\nQuantum mechani cs is traditionally considered when measuring at the extreme microscopic s cale\, i.e. single photons\, electrons or atoms. However\, even the early pioneers of the quantum theory postulated gedanken experiments in which q uantum effects would manifest on an everyday scale. I will present recent experiments in which we engineer and measure microelectromechanical (MEMs) circuits to observe and to exploit quantum behavior at an increasingly ma croscopic scale. By embedding mechanical resonators in superconducting mi crowave circuits\, we achieve strong radiation-pressure coupling between f ields and motion that allows us to perform quantum experiments of massive objects. I will present our recent experimental demonstration of determin istic macroscopic entanglement\, as well as ongoing efforts toward arbitra ry quantum control of mechanical systems. The ability to prepare and to “listen” to quantum sound has implications for fundamental science as well as many powerful applications including the processing\, storage and networking of quantum information.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/38/ END:VEVENT BEGIN:VEVENT SUMMARY:Ricardo Puebla Antunes\, Clara Wanjura & John Price (IFF-CSIC\, U niversity of Cambridge\, Imperial College London) DTSTART:20210526T130000Z DTEND:20210526T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/39 DESCRIPTION:Title: Frontiers talks on State Preperation & Control\nby Ric ardo Puebla Antunes\, Clara Wanjura & John Price (IFF-CSIC\, University o f Cambridge\, Imperial College London) as part of UniKORN seminars\n\n\nAb stract\nTalk 1: Quantum control in spin-boson systems via shortcuts to adi abaticity by Ricardo Puebla Antunes\n\n \nAbstract: The design of fast and robust time-dependent protocols to control quantum systems is one of the main challenges in quantum state preparation\, and thus essential for the development of technologies aiming at harnessing quantum effects. Among th e different strategies that have been put forward in this context\, an adi abatic control of the system's parameters merits special attention thanks to its simplicity and its ability to typically provide useful and interest ing quantum states. However\, such adiabatic control is prone to decoheren ce effects as it can only be achieved by slowly varying the system's param eters\, that is\, in a time scale generally larger than the decoherence ti me. Yet\, it has been recently shown that the result of an adiabatic contr ol can be exactly obtained in an arbitrary time by employing a suitable pr otocol\, i.e. by taking a shortcut [1]. This sped-up adiabatic control\, or as commonly known\, the shortcut to adiabaticity allows therefore to re alize the desired protocol before decoherence effects become significant\, but it comes at the price of demanding both more tunability and control o n the system of interest. In this talk I will focus on the application of protocols built on shortcuts to adiabaticity to generate non-classical sta tes of a bosonic mode exploiting a coherent exchange of excitations with a two-level system ruled by a Jaynes-Cummings interaction mechanism [2]. Th ese protocols allow for the generation of arbitrary Fock states of the bos onic mode\, as well as coherent quantum superpositions of a Schrödinger c at-like form. In addition\, I will illustrate how to obtain a class of pho ton-shifted states where the vacuum population is removed\, a result akin to photon addition\, but displaying more non-classicality than standard ph oton-added states. \n\n[1] D. Guéry-Odelin\, et al.\, Rev. Mod. Phys. 91 \, 045001 (2019)\n\n[2] O. Abah\, R. Puebla\, and M. Paternostro\, Phys. R ev. Lett. 124\, 180401 (2020)\n\n\n--------------------------------------- ----------------------------------------------------\n\n\nSpeaker 2: Title : Topological framework for directional amplification in driven-dissipativ e cavity arrays by Clara Wanjura\n\n\nAbstract: Directional amplification\ , in which signals are selectively amplified depending on their propagatio n direction\, has attracted much attention as key resource for application s\, including quantum information processing. Recently\, several\, physica lly very different\, directional amplifiers have been proposed and realize d in the lab.\n\nIn this talk\, I will present a unifying framework based on topology to understand non-reciprocity and directional amplification in driven-dissipative cavity arrays [1]. Specifically\, we have shown that t here is a one-to-one correspondence between a non-zero invariant of non-He rmitian topology defined on the spectrum of the dynamic matrix and regimes of directional amplification\, in which the end-to-end gain grows exponen tially with the number of cavities. Our framework allows us to analyticall y compute the scattering matrix\, the gain and reverse gain which explicit ly depend on the value of the topological invariant. Parameter regimes ach ieving directional amplification can be elegantly obtained from a topologi cal ‘phase diagram’\, which provides a guiding principle for the desig n of both phase-preserving and phase-sensitive multimode directional ampli fiers.\n\nRealistic systems are always subject to disorder. I will show\, however\, that topological\, directional amplification is extremely robust against disorder [2]. Indeed\, the separation between the complex spectru m and the origin (the size of the point gap) determines the amount of tole rated disorder. Furthermore\, we have shown that the zero reverse gain ass ociated with exceptional points remains exactly zero in the presence of ar bitrary on-site disorder.\n\n\n[1] C. C. Wanjura\, M. Brunelli\, A. Nunnen kamp. Topological framework for directional amplification in driven-dissip ative cavity arrays. Nat Commun 11\, 3149 (2020).\n\n[2] C. C. Wanjura\, M . Brunelli\, A. Nunnenkamp. Correspondence between non-Hermitian topology and directional amplification in the presence of disorder (2020). Preprint at https://arxiv.org/abs/2010.14513\n\n\n-------------------------------- -----------------------------------------------------------\n\nTalk 3: Sin gle- and multi-phonon subtraction in whispering-gallery-mode\nmicroresonat ors by John Price\n\n\nAbstract: Brillouin scattering in optical microreso nators offers a promising avenue for quantum optomechanics applications ow ing to several favourable properties including: high mechanical frequencie s\, strong optomechanical coupling\, and low optical absorption and heatin g. Our lab is utilising these properties to perform measurement-based stat e preparation and readout of mechanical motional states. In this talk I wi ll discuss recent experiments combining photon counting and optical hetero dyne detection\, where we perform single- and multiphonon subtraction to a whispering-gallery-mode Brillouin\noptomechanical system. We observe that these operations counterintuitively approximately double and triple the m ean occupation of the state\, respectively [1]. Furthermore\, we reconstru ct the sparameterised Wigner phase-space distribution\, and the observe th e resulting non-Gaussianity in the prepared states [2].\n\n[1] G. Enzian\, L. Freisem\, J. J. Price\, J. Nunn\, J. Janousek\, B. C. Buchler\, P. K. Lam\, and M. R. Vanner “Single-Phonon Addition and Subtraction to a Mech anical Thermal State\,” Physical Review Letters 126\, 033601 (2021).\n\n [2] G. Enzian\, L. Freisem\, J. J. Price\, A. Ø. Svela\, J. Clarke\, B. S hajilal\, J. Janousek\, B. C. Buchler\, P. K. Lam\, and M. R. Vanner\, “ Non-Gaussian mechanical motion via single and multi-phonon subtraction fro m a thermal state\,” arxiv:2103.05175\, (2021).\n\nChaired by Saba Khan. \n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/39/ END:VEVENT BEGIN:VEVENT SUMMARY:Tracy Northup\, Yuwen Chu\, Ewold Verhagen\, Andre Xuereb DTSTART:20210609T130000Z DTEND:20210609T143000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/40 DESCRIPTION:Title: Panel discussion on "Beyond the Quantum Ground State"\ nby Tracy Northup\, Yuwen Chu\, Ewold Verhagen\, Andre Xuereb as part of U niKORN seminars\n\n\nAbstract\nThis panel discussion will explore mechanic al systems “beyond the ground state” drawing on expertise and knowledg e from neighbouring fields. We will be specifically interested in understa nding how to create non-classical states of macroscopic mechanical oscilla tors. How to characterize quantum states and identify nonclassicality? Wha t are the roles of open-system dynamics? What are the spectrum of experime ntal and theoretical tools currently at our disposal? The panellists will draw on state-of-the-art results\, as well as their expertise of neighbour ing fields such as atomic ions\, superconducting qubits\, and quantum opti cs.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/40/ END:VEVENT BEGIN:VEVENT SUMMARY:Poster session I DTSTART:20210616T130000Z DTEND:20210616T143000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/41 DESCRIPTION:Title: UniKORN Virtual Poster Session\nby Poster session I as part of UniKORN seminars\n\n\nAbstract\nTo round off a year of virtual se minars\, UniKORN is organising the two virtual poster sessions. They will be held on the 16th and 23rd of June at 14:00-15:30 BST online on the Gath er Town platform\, where you can network and socialise with other optomech anics researchers. We encourage everyone to join in and submit a poster\, but we particularly encourage PhD students and postdocs to join.\n\n \nIn each session\, we will select a poster for a £100 book voucher poster pri ze. The judges include representatives from the British Optomechanics Rese arch Network\, Nature and EPSRC.\n\n \nTo register for the poster sessions \, please fill out the above form. Note that you will not be able to join the session unless you have registered using the form. The Registration de adline for poster submissions is the 2nd of June 2021.\n \nWe aim for both sessions to have an equal number of people and will try our best to alloc ate the posters accordingly. More information\, including specifications a nd instructions on how to upload your poster will be sent out in the two w eeks prior to the event.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/41/ END:VEVENT BEGIN:VEVENT SUMMARY:Poster session II DTSTART:20210623T130000Z DTEND:20210623T143000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/42 DESCRIPTION:Title: UniKORN Virtual Poster Session\nby Poster session II a s part of UniKORN seminars\n\n\nAbstract\nTo round off a year of virtual s eminars\, UniKORN is organising the two virtual poster sessions. They will be held on the 16th and 23rd of June at 14:00-15:30 BST online on the Gat her Town platform\, where you can network and socialise with other optomec hanics researchers. We encourage everyone to join in and submit a poster\, but we particularly encourage PhD students and postdocs to join.\n\n \nIn each session\, we will select a poster for a £100 book voucher poster pr ize. The judges include representatives from the British Optomechanics Res earch Network\, Nature and EPSRC.\n\n \nTo register for the poster session s\, please fill out the above form. Note that you will not be able to join the session unless you have registered using the form. The Registration d eadline for poster submissions is the 2nd of June 2021.\n \nWe aim for bot h sessions to have an equal number of people and will try our best to allo cate the posters accordingly. More information\, including specifications and instructions on how to upload your poster will be sent out in the two weeks prior to the event.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/42/ END:VEVENT BEGIN:VEVENT SUMMARY:Carla Faria and Charles Adams DTSTART:20210630T130000Z DTEND:20210630T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/43 DESCRIPTION:Title: A conversation on: How do you run a research group?\nb y Carla Faria and Charles Adams as part of UniKORN seminars\n\n\nAbstract\ nJoin us for this conversation on how you build and manage a research grou p together with Prof Carla Faria and Prof Charles Adams. The session will be chaired by Dr Xavier Rojas.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/43/ END:VEVENT BEGIN:VEVENT SUMMARY:Panel discussion DTSTART:20210707T130000Z DTEND:20210707T143000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/44 DESCRIPTION:Title: Panel discussion: How do you build a research network? \nby Panel discussion as part of UniKORN seminars\n\n\nAbstract\nPlease jo in us for this discussion on "How do you build a research network?". We ar e pleased to welcome participants from the Knowledge Transfer Network\, Th e Blackett Lab Family\, the Marie Sklodowska-Curie Action Alumni network\, and EPSRC.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/44/ END:VEVENT BEGIN:VEVENT SUMMARY:Marko Toroš\, Philipp Treutlein (University of Glasgow\, Universi ty of Basel) DTSTART:20211006T130000Z DTEND:20211006T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/47 DESCRIPTION:Title: Creating atom-nanoparticle quantum superposition & Couplin g quantum systems with a laser loop\nby Marko Toroš\, Philipp Treutle in (University of Glasgow\, University of Basel) as part of UniKORN semina rs\n\n\nAbstract\nMarko Toroš: Creating atom-nanoparticle quantum superpo sition\n\nHybrid optomechanical systems offer a unique potential for quant um technologies as well as for exploring the boundaries of quantum mechani cs. In this talk I will present an atom-nanoparticle hybrid system that ca n be used as a matter-wave probe of external fields [1]. I will show how t o control a large ∼500-nm nanoparticle using the internal state of the a tom so as to create\, as well as detect\, non-classical motional states of the nanoparticle. Specifically\, I will consider a setup based on a silic a nanoparticle coupled to a Cesium atom and discuss a protocol for prepari ng and verifying a Schrödinger-cat state of the nanoparticle that does no t require cooling to the motional ground state. I will finally show that t he existence of the superposition can be revealed using the Earth's gravit ational field using a method that is insensitive to the most common source s of decoherence and works for any initial state of the nanoparticle.\n\n[ 1] M. Toroš\, S. Bose\, and P. F. Barker\, Creating atom-nanoparticle qua ntum superposition\, Phys. Rev. Research 3\, 033218 (2021)\n\n------------ -------------------------------------------------------------------------- -----\n\n\nPhilipp Treutlein: Coupling quantum systems with a laser loop\n \nMany of the breakthroughs in quantum science and technology rely on engi neering strong Hamiltonian interactions between quantum systems. Typically \, strong coupling relies on short-range forces or on placing the systems in high-quality electromagnetic resonators\, which restricts the range of the coupling to short distances. In this talk I will show how a loop of la ser light can generate Hamiltonian coupling over a distance [1] and report experiments using this approach to strongly couple a nanomechanical membr ane oscillator and an atomic spin ensemble across one meter in a room-temp erature environment [2]. We observe spin-membrane normal mode splitting\, coherent energy exchange oscillations\, two-mode thermal noise squeezing\, dissipative coupling with exceptional points\, and sympathetic cooling of the membrane. Our experiments demonstrate the versatility and flexibility of light-mediated interactions\, a powerful tool for quantum science that offers many further possiblities and is readily applicable to a variety o f different systems.\n\n[1] T. M. Karg\, B. Gouraud\, P. Treutlein\, and K . Hammerer\, Remote Hamiltonian interactions mediated by light\, Phys. Rev . A 99\, 063829 (2019).\n\n[2] T. M. Karg\, B. Gouraud\, C. T. Ngai\, G.-L . Schmid\, K. Hammerer\, and P. Treutlein\, Light-mediated strong coupling between a mechanical oscillator and atomic spins one meter apart\, Scienc e 369\, 174 (2020).\n\nChaired by Peter Barker.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/47/ END:VEVENT BEGIN:VEVENT SUMMARY:Cindy Regal\, Yiwen Chu\, Florian Marquardt\, Peter Rabl (Universi ty of Colorado Boulder\, ETH Zurich\, MPI for Science of Light\, TU Wien) DTSTART:20211013T130000Z DTEND:20211013T143000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/48 DESCRIPTION:Title: Panel discussion on hybrid optomechanics\nby Cindy Reg al\, Yiwen Chu\, Florian Marquardt\, Peter Rabl (University of Colorado Bo ulder\, ETH Zurich\, MPI for Science of Light\, TU Wien) as part of UniKOR N seminars\n\n\nAbstract\nThe panel discussion will make an attempt at eva luating the current state of the art of hybrid optomechanics and giving ne w input by tackling open questions and combining different perspectives. T he virtual floor will be opened for audience participation in the form of questions or discussion points after some initial moderated discussion.\n\ nChaired by Edward Laird (Lancaster University)\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/48/ END:VEVENT BEGIN:VEVENT SUMMARY:Juliette Monsel\, Mauro Paternostro DTSTART:20211103T140000Z DTEND:20211103T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/49 DESCRIPTION:Title: Block 7 - Nonequilibrium Physics and Nano thermodynamics: ECR + Introduction\nby Juliette Monsel\, Mauro Paternostro as part of UniKORN seminars\n\n\nAbstract\nFrontiers Talk - By Juliette Monsel\n\n\nA bstract:\n\nOptomechanical cooling with coherent and squeezed light: The t hermodynamic cost of opening the heat valve\n\nGround-state cooling of mec hanical motion by coupling to a driven optical cavity has been demonstrate d in various optomechanical systems. In our paper\, we provide a thermodyn amic performance analysis of optomechanical sideband cooling in terms of a heat valve. As performance quantifiers\, we examine not only the lowest r eachable effective temperature (phonon number) but also the evacuated-heat flow as an equivalent to the cooling power of a standard refrigerator\, a s well as appropriate thermodynamic efficiencies\, which all can be experi mentally inferred from measurements of the cavity output light field. Impo rtantly\, in addition to the standard optomechanical setup fed by coherent light\, we investigate two recent alternative setups for achieving ground -state cooling: replacing the coherent laser drive by squeezed light or us ing a cavity with a frequency-dependent (Fano) mirror. We study the dynami cs of these setups within and beyond the weak-coupling limit and give conc rete examples based on parameters of existing experimental systems. By app lying our thermodynamic framework\, we gain detailed insights into these t hree different optomechanical cooling setups\, allowing a comprehensive un derstanding of the thermodynamic mechanisms at play [1].\n\n[1] J. Monsel\ , N. Dashti\, S. K. Manjeshwar\, J. Eriksson\, H. Ernbrink\, E. Olsson\, E . Torneus\, W. Wieczorek\, J. Splettstoesser: Phys. Rev. A 103\, 063519 (2 021)\n\n\n----------------------- \n\nPerspectives Talk - By Mauro Paterno stro\n\nAbstract: Non-equilibrium thermodynamics of quantum processes -- a n optomechanical perspective\n\nI will give a high-level introduction to n on-equilibrium thermodynamics of quantum systems and processes\, building the case for its optomechanical exploration. I will illustrate recent achi evements and possible ways forward made available by the control that is c urrently possible in such platform.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/49/ END:VEVENT BEGIN:VEVENT SUMMARY:Janet Anders\, Raúl Rica\, Raam Uzdin\, Nikolai Kiesel (Universit y of Exeter\, University of Granada\, Hebrew University of Jerusalem\, Uni versity of Vienna) DTSTART:20211110T140000Z DTEND:20211110T153000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/52 DESCRIPTION:Title: Panel discussion on Optomechanical Machines\nby Janet Anders\, Raúl Rica\, Raam Uzdin\, Nikolai Kiesel (University of Exeter\, University of Granada\, Hebrew University of Jerusalem\, University of Vie nna) as part of UniKORN seminars\n\n\nAbstract\nPanel discussion on ‘Opt omechanical machines'. We are delighted to present Janet Anders\, Raúl Ri ca\, Raam Uzdin and Nikolai Kiesel as the panellist.\n\nChaired by James M illen.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/52/ END:VEVENT BEGIN:VEVENT SUMMARY:Otto Muskens\, Mika Sillanpää (University of Southampton\, Aalto University) DTSTART:20211201T140000Z DTEND:20211201T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/54 DESCRIPTION:Title: Block 8 - Nanofabricating optomechanics\nby Otto Muske ns\, Mika Sillanpää (University of Southampton\, Aalto University) as pa rt of UniKORN seminars\n\n\nAbstract\nFrontiers talk by Otto Muskens\n\nTi tle: “What’s the meta with optomechanical metasurfaces”\n\nAbstract: Metamaterials have been invented as man-made artificial materials with ne w properties often unattainable in natural materials. Metamaterials typica lly consist of optically resonant building blocks (metamolecules) stacked together to achieve an effective optical response. Metasurfaces represent a sub-category of devices where a single layer of metamolecules allow cont rol over wavefronts with many new applications in e.g. flat optics\, holog rams and frequency selective surfaces. Combining the degrees of freedom of fered by metasurfaces with optomechanics is of interest for achieving extr emely nonlinear devices where vibrations and light are coupled together. W e have investigated metasurfaces where the fundamental metamolecules suppo rt both optical and gigahertz vibrational resonances. Devices were fabrica ted using focused ion-beam milling in a 300nm thick free-standing silicon carbide (SiC) membrane. We use optical pump-probe spectroscopy to impulsiv ely excite the vibrational modes though a metasurface optical resonance. D etection takes place with a second\, time-delayed pulse at a different wav elength corresponding to another optically resonant mode\, thus benefiting from the enhanced sensitivity of the metasurface. Our results on waveleng th and polarization-dependent excitation of vibrations are interpreted usi ng an optical force-induced excitation mechanism. We explore the local var iations of the vibrational modes over the metasurface\, and show that the response is characterised by an inhomogeneous distribution of vibrational frequencies related to local variations in nanofabrication and membrane ch aracteristics. This study reveals some of the challenges and opportunities offered by combining optical and mechanical metasurfaces in the regime of high mechanical frequencies.\n\n\nIntroductory talk by Mika Sillanpää \ n\nTitle: (Microwave) optomechanics in the quantum regime\n\nAbstract: Mec hanical oscillators affected by radiation pressure forces allow to address fundamental questions on quantum properties of moving objects\, or\, to e xplore quantum limits in measurements. Additionally\, micro- or nanomechan ical devices have shown strong promise for supporting components in quantu m technology\, for example\, for communication and information storage. An interesting setup for cavity optomechanics consists of superconducting on -chip microwave cavities coupled to a micromechanical vibrating membranes. After an introduction to (microwave) optomechanics in the quantum regime\ , I show how it is possible to measure a mechanical oscillator without qua ntum back-action of the measurement by constructing one effective oscillat or from two physical oscillators. We realize such a quantum mechanics-free subsystem in microwave optomechanics\, and show the measurements of two c ollective quadratures while evading the quantum back-action by 8 decibels on both of them\, obtaining a total noise within a factor of 2 of the full quantum limit. By perturbing the measurement slightly\, such measurements could be used to generate stabilized entanglement between two macroscopic mechanical oscillators. This prepares a canonical entangled state known a s the two-mode squeezed state. It corresponds to the variances of collecti ve position and momentum quadratures being reduced below the quantum zero- point fluctuations level. Moreover\, our approach allows for full tomograp hic characterization of the prepared entangled state. We carry out this me asurement\, and verify the existence of entanglement in the steady state b y direct access to fluctuations in all the collective motional quadratures .\n\nChaired by Xavier Rojas.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/54/ END:VEVENT BEGIN:VEVENT SUMMARY:Panel discussion: Paul Seidler\, Prof Pavel Ginzburg\, John R. Law all\, Prof Shankar Kumar and Guilhem Madiot (IBM Research\,Tel Aviv Univer sity\, NIST\, IISc and ICN2) DTSTART:20211208T140000Z DTEND:20211208T153000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/55 DESCRIPTION:Title: Block 8 - Nanofabricating optomechanics\nby Panel disc ussion: Paul Seidler\, Prof Pavel Ginzburg\, John R. Lawall\, Prof Shankar Kumar and Guilhem Madiot (IBM Research\,Tel Aviv University\, NIST\, IISc and ICN2) as part of UniKORN seminars\n\n\nAbstract\nRecent developments in nanofabrication technology have provided a unique platform - from extre mely sensitive on-chip sensing to exploring foundational questions in quan tum mechanics. This discussion will explore the impact of modern nanotechn ology on optomechanical research.\n\nChaired by Sergey Kafanov.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/55/ END:VEVENT BEGIN:VEVENT SUMMARY:Vittorio Peano (Max Planck Institute for the Science of Light) DTSTART:20220117T100000Z DTEND:20220117T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/56 DESCRIPTION:Title: Lecture Series on Cavity Optomechanics: From basics concep ts to advanced applications\nby Vittorio Peano (Max Planck Institute for the Science of Light) as part of UniKORN seminars\n\n\nAbstract\nMonda y: Motivation\, radiation forces\, optomechanical Hamiltonian\, and optome chanical platforms\n\n---------------------------------------------------- \n\nLecture Abstract: \n\nThe tail of a comet always points away from the sun. Back in the 17th century\, Kepler explained this observation proposi ng that light exerts a force on matter\, the so-called radiation pressure force. Four hundred years later technological progress has allowed studyi ng this force in a completely different playground: high-finesse cavities allow to concentrate very high radiation intensities on lightweight mecha nical devices that are exceptionally well shielded from the neighbouring e nvironment. In these cavity-optomechanics platforms\, the radiation press ure force can have a strong impact on the mechanical component on a time s cale that can be shorter than the typical time for absorbing a single phon on from the environment. This has allowed reaching landmark achievements l ike cooling a mechanical oscillator to its ground state\, squeezing the el ectromagnetic vacuum and measuring gravitational waves. In this series of lectures\, I will give a didactic overview of the field of cavity optomech anics.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/56/ END:VEVENT BEGIN:VEVENT SUMMARY:Vittorio Peano (Max Planck Institute for the Science of Light) DTSTART:20220118T100000Z DTEND:20220118T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/57 DESCRIPTION:Title: Lecture Series on Cavity Optomechanics: From basics concep ts to advanced applications\nby Vittorio Peano (Max Planck Institute for the Science of Light) as part of UniKORN seminars\n\n\nAbstract\nTuesd ay: Precision sensing\, gravitational interferometers and standard quantum limit\n\n----------------------------------------------------\n\nLecture Abstract: \n\nThe tail of a comet always points away from the sun. Back i n the 17th century\, Kepler explained this observation proposing that ligh t exerts a force on matter\, the so-called radiation pressure force. Four hundred years later technological progress has allowed studying this forc e in a completely different playground: high-finesse cavities allow to co ncentrate very high radiation intensities on lightweight mechanical device s that are exceptionally well shielded from the neighbouring environment. In these cavity-optomechanics platforms\, the radiation pressure force ca n have a strong impact on the mechanical component on a time scale that ca n be shorter than the typical time for absorbing a single phonon from the environment. This has allowed reaching landmark achievements like cooling a mechanical oscillator to its ground state\, squeezing the electromagneti c vacuum and measuring gravitational waves. In this series of lectures\, I will give a didactic overview of the field of cavity optomechanics.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/57/ END:VEVENT BEGIN:VEVENT SUMMARY:Vittorio Peano (Max Planck Institute for the Science of Light) DTSTART:20220119T100000Z DTEND:20220119T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/58 DESCRIPTION:Title: Lecture Series on Cavity Optomechanics: From basics concep ts to advanced applications\nby Vittorio Peano (Max Planck Institute for the Science of Light) as part of UniKORN seminars\n\n\nAbstract\nWedne sday: Basic physical effects\, squeezing\, cooling\, entanglement\n\n----- -----------------------------------------------\n\nLecture Abstract: \n\nT he tail of a comet always points away from the sun. Back in the 17th cent ury\, Kepler explained this observation proposing that light exerts a forc e on matter\, the so-called radiation pressure force. Four hundred years later technological progress has allowed studying this force in a complete ly different playground: high-finesse cavities allow to concentrate very high radiation intensities on lightweight mechanical devices that are exce ptionally well shielded from the neighbouring environment. In these cavit y-optomechanics platforms\, the radiation pressure force can have a strong impact on the mechanical component on a time scale that can be shorter th an the typical time for absorbing a single phonon from the environment. Th is has allowed reaching landmark achievements like cooling a mechanical os cillator to its ground state\, squeezing the electromagnetic vacuum and me asuring gravitational waves. In this series of lectures\, I will give a di dactic overview of the field of cavity optomechanics.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/58/ END:VEVENT BEGIN:VEVENT SUMMARY:Vittorio Peano (Max Planck Institute for the Science of Light) DTSTART:20220120T100000Z DTEND:20220120T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/59 DESCRIPTION:Title: Lecture Series on Cavity Optomechanics: From basics concep ts to advanced applications\nby Vittorio Peano (Max Planck Institute for the Science of Light) as part of UniKORN seminars\n\n\nAbstract\nThurs day: Multimode optomechanics including applications like routers and frequ ency conversions\n\n----------------------------------------------------\n \nLecture Abstract: \n\nThe tail of a comet always points away from the su n. Back in the 17th century\, Kepler explained this observation proposing that light exerts a force on matter\, the so-called radiation pressure fo rce. Four hundred years later technological progress has allowed studying this force in a completely different playground: high-finesse cavities a llow to concentrate very high radiation intensities on lightweight mechani cal devices that are exceptionally well shielded from the neighbouring env ironment. In these cavity-optomechanics platforms\, the radiation pressur e force can have a strong impact on the mechanical component on a time sca le that can be shorter than the typical time for absorbing a single phonon from the environment. This has allowed reaching landmark achievements lik e cooling a mechanical oscillator to its ground state\, squeezing the elec tromagnetic vacuum and measuring gravitational waves. In this series of le ctures\, I will give a didactic overview of the field of cavity optomechan ics.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/59/ END:VEVENT BEGIN:VEVENT SUMMARY:Vittorio Peano (Max Planck Institute for the Science of Light) DTSTART:20220121T100000Z DTEND:20220121T113000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/60 DESCRIPTION:Title: Lecture Series on Cavity Optomechanics: From basics concep ts to advanced applications\nby Vittorio Peano (Max Planck Institute for the Science of Light) as part of UniKORN seminars\n\n\nAbstract\nFrida y: Nonlinear and topological optomechanics\n\n---------------------------- ------------------------\n\nLecture Abstract: \n\nThe tail of a comet alwa ys points away from the sun. Back in the 17th century\, Kepler explained this observation proposing that light exerts a force on matter\, the so-ca lled radiation pressure force. Four hundred years later technological pro gress has allowed studying this force in a completely different playground : high-finesse cavities allow to concentrate very high radiation intensit ies on lightweight mechanical devices that are exceptionally well shielded from the neighbouring environment. In these cavity-optomechanics platfor ms\, the radiation pressure force can have a strong impact on the mechanic al component on a time scale that can be shorter than the typical time for absorbing a single phonon from the environment. This has allowed reaching landmark achievements like cooling a mechanical oscillator to its ground state\, squeezing the electromagnetic vacuum and measuring gravitational w aves. In this series of lectures\, I will give a didactic overview of the field of cavity optomechanics.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/60/ END:VEVENT BEGIN:VEVENT SUMMARY:Amir Youssefi\; Ewold Verhagen (EPFL Lausanne\, Switzerland\; Cent er for Nanophotonics\, AMOLF\, Amsterdam\, The Netherlands) DTSTART:20220202T140000Z DTEND:20220202T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/61 DESCRIPTION:Title: Superconducting circuit optomechanics in topological latti ces & Hermitian and non-Hermitian topology in nano-optomechanical networks \nby Amir Youssefi\; Ewold Verhagen (EPFL Lausanne\, Switzerland\; Cen ter for Nanophotonics\, AMOLF\, Amsterdam\, The Netherlands) as part of Un iKORN seminars\n\n\nAbstract\nFrontiers Talk by Amir Youssefi & Introducto ry Talk by Ewold Verhagen\n\n1) Frontiers Talk by Amir Youssefi:\n\nTitle: Superconducting circuit optomechanics in topological lattices\n\nAbstract :\nQuantum optomechanics allows controlling mechanical motion\, via the in teraction with electromagnetic radiation. Over the past decades\, optomech anics has allowed major progress in the quantum control of engineered mech anical systems ranging from ground-state cooling and entanglement of mecha nical objects to precise position measurements. Yet\, nearly all prior sch emes have employed single- or few mode optomechanical systems. In contrast \, novel dynamics and applications are expected when utilizing optomechani cal arrays and lattices.\n\nSuperconducting circuits are a promising platf orm to realize optomechanics with a flexible design and precise control. T o date\, however\, realizing optomechanical lattices has been compounded b y the limited scaling in contemporary circuit optomechanics.\nIn this talk \, I explain how we overcome this challenge to realize superconducting cir cuit optomechanical lattices. We demonstrated non-trivial topological mode s in a 10 site optomechanical chain as well as a 24 site honeycomb lattice \, realizing the well-known Su-Schrieffer-Heeger (SSH) model. Furthermore\ , I present a technique exploiting embedded optomechanical interaction to directly measure the collective microwave modeshape\, without using any lo cal probe or inducing perturbation. Our new platform accompanied by the me asurement techniques introduced offers an avenue to explore many-body phys ics in optomechanical lattices such as quantum and classical collective dy namics\, quantum entanglement\, and topological behaviors to name a few.\n \n\n\n2) Introductory Talk by Ewold Verhagen:\n\nTitle: Hermitian and non- Hermitian topology in nano-optomechanical networks\n\nAbstract: The toolbo x of optomechanical interactions yields powerful new ways to control the f low of photons and phonons\, in systems that involve more than a single op tical and mechanical mode. Suitable laser fields can couple these degrees of freedom\, creating bosonic networks that can be reconfigured at will\, and imbuing unusual behavior that cannot be found in regular\, passive pho tonic or phononic systems. The fact that optomechanical control fields can readily convert frequencies allows the effective breaking of time-reversa l symmetry\, leading to nonreciprocal behavior like isolation and circulat ion. We study how the created synthetic magnetic fields in optomechanical networks lead to states and transport behavior that mimics the quantum Hal l effect for electrons – a canonical form of a topological insulator. In terestingly\, the fact that optomechanical interactions can additionally i nduce nonlinearity as well as controlled gain and loss (non-Hermiticity) l eads to behavior that does not have counterparts in electronic materials. Specifically\, we show that the introduction of optomechanical squeezing i n nanomechanical networks with broken time-reversal symmetry leads to new types of synthetic gauge fields\, that control the non-Hermitian dynamics of the networks in unusual ways. They could form the building blocks of no vel non-Hermitian topological phases with applications in topological ampl ifiers and nanomechanical sensing.\n\nChaired by Clara Wanjura.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/61/ END:VEVENT BEGIN:VEVENT SUMMARY:Tirth Shah\; Aash Clerk (Max Planck Institute for the Science of L ight\, Erlangen\, Germany\; University of Chicago\, USA) DTSTART:20220216T140000Z DTEND:20220216T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/62 DESCRIPTION:Title: Topological phonon transport in an optomechanical system\; Non-Hermitian quantum dynamics: from sensing to non-equilibrium steady s tates\nby Tirth Shah\; Aash Clerk (Max Planck Institute for the Scienc e of Light\, Erlangen\, Germany\; University of Chicago\, USA) as part of UniKORN seminars\n\n\nAbstract\nTalks by Tirth Shah & Aash Clerk\n\n1) Tir th Shah\n\nTitle: Topological phonon transport in an optomechanical system \n\nAbstract: Recent advances in cavity optomechanics have now made it pos sible to use light to measure mechanical motion down to the individual pho nons. At the same time\, microfabrication techniques have enabled small-sc ale on-chip optomechanical circuits. Motivated by these developments\, sev eral theoretical works have envisioned larger scale optomechanical systems where light is used to steer and detect on-chip topological vibrations. I n this talk\, I will present our work [1] on the observation of topologica l phonon transport within a multiscale optomechanical crystal structure co nsisting of an array of over 800 cavity-optomechanical elements. Using sen sitive\, spatially resolved optical read-out\, we detect thermal phonons i n a 0.325−0.34 GHz band traveling along a topological edge channel\, wit h substantial reduction in backscattering. This work further advances the ongoing effort to miniaturize topological phononic devices down to the nan oscale\, opening the way to GHz frequency acoustic wave circuits comprisin g robust delay lines and non-reciprocal elements.\n\n[1] Ren\, H.\, Shah\, T.\, Pfeifer\, H.\, Brendel\, C.\, Peano\, V.\, Marquardt\, F.\, & Painte r\, O. (2020). Topological phonon transport in an optomechanical system. a rXiv preprint arXiv:2009.06174.\n\n2) Aash Clerk\n\nTitle: Non-Hermitian q uantum dynamics: from sensing to non-equilibrium steady states\n\nAbstrac t: Extended lattice systems where the propagation of waves or particles is described by an effective non-Hermitian Hamiltonian can exhibit a myriad of unusual properties\, including a dramatic sensitivity to boundary condi tions. This effect (known as the “non-Hermitian skin effect”) goes be yond the standard bulk-boundary correspondence of conventional topologica l systems. The non-Hermitian dynamics required here ultimately correspond s to realizing structured loss and gain processes that yield directional d ynamics\, and hence is within reach of several optomechanical platforms. In this talk\, I’ll give an introduction to some of the basic ideas in t his field\, and discuss recent work on how these effects manifest themselv es in fully quantum settings. I’ll discuss both an application to enhan ced quantum parameter sensing (where one can enhance sensitivity exponenti ally with the length of the lattice)\, and work discussing how these non-H ermitian effective Hamiltonians can yield surprising kinds of non-thermal equilibrium steady states.\n\nChaired by Clara Wanjura.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/62/ END:VEVENT BEGIN:VEVENT SUMMARY:Michael Vanner (Imperial College London) DTSTART:20220309T140000Z DTEND:20220309T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/63 DESCRIPTION:Title: Brillouin optomechanics in whispering-gallery-mode microre sonators:\nby Michael Vanner (Imperial College London) as part of UniK ORN seminars\n\n\nAbstract\nBackward Brillouin scattering in whispering-ga llery-mode micro-resonators offers an exciting avenue to pursue both class ical and quantum optomechanics applications. Our team—the Quantum Measur ement Lab—together with our collaborators\, are currently exploring this regime and the favourable properties it affords for non-Gaussian motional state preparation of the acoustic field. In particular\, the high mechani cal frequencies\, mechanical mode selectivity\, and low optical absorption provide a promising route to overcome current hindrances within optomecha nics. Three of our recent results in this area include: the observation of Brillouin optomechanical strong coupling [1]\, single-phonon addition and subtraction to a thermal state of the acoustic field [2]\, and advancing the state-of-the-art of mechanical state tomography to observe the non-Gau ssian states generated by single- and multi-phonon subtraction [3]. This t alk will cover these three results\, what they enable\, and the broader di rection of our lab including the prospects of this platform for quantum-me mory applications.\n\nWeb: www.qmeas.net\n\n[1] G. Enzian et al. Optica 6\ , 7 (2019).\n\n[2] G. Enzian et al. Phys. Rev. Lett. 126\, 033601 (2021).\ n\n[3] G. Enzian\, L. Freisem\, J. J. Price\, A. Ø. Svela et al. Phys. Re v. Lett. 127\, 243601 (2021).\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/63/ END:VEVENT BEGIN:VEVENT SUMMARY:Niccolò Fiaschi\; Andrei Rakhubovskiy (TU Delft\, Palacký Univer sity) DTSTART:20220316T140000Z DTEND:20220316T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/64 DESCRIPTION:Title: Routing quantum information via optomechanical devices & O ptimal generation and detection of nonclassical correlations in levitated optomechanics\nby Niccolò Fiaschi\; Andrei Rakhubovskiy (TU Delft\, P alacký University) as part of UniKORN seminars\n\n\nAbstract\n*TALK ONE* by Niccolo Fiaschi\n\nTitle: Routing quantum information via optomechanica l devices\n\n\nAbstact: Using acoustic phonons -- quantized traveling mech anical wavepackets -- as a medium to transmit quantum states is currently gaining significant attention\, due to the orders-of-magnitude lower energ y phonons require compared to other carriers\, such as electrons or optica l photons. Moreover\, phonons are highly promising candidates to connect h eterogeneous quantum systems on a chip\, such as microwave and optical pho tons\, potentially enabling long distances transmission of the quantum sta tes of microwave-frequency quantum systems via optical fibers.\n\n In this talk we describe the latest works in the Groeblacher Laboratories in TU D elft\, a Optomechanical Quantum Teleportation for long distance quantum re peaters and On-Chip Phononic Distribution of Quantum Information for short distance routing.\n\n*TALK TWO* by Andrei Rakhubovskiy\n\n\nTitle: Optima l generation and detection of nonclassical correlations in levitated optom echanics\n\nAbstract: Nonclassical correlations provide a resource for man y applications in quantum technology\nas well as providing strong evidence that a system is indeed operating in the quantum regime.\nOptomechanical systems can be arranged to generate quantum entanglement between the mecha nics and a mode of traveling light.\nHere we propose automated optimizatio n of the production of quantum correlations in such a system\, beyond what can be achieved through analytical methods\, by applying Bayesian optimiz ation to the control parameters.\nFurthermore\, by adding the temporal pro file of the detected light modes to the parameter space\, we observe an in crease in the magnitude of the correlations.\nThis indicates the importanc e of accurate designation of the light modes of interest for the detection of the correlations.\nWe also observe that our optimization approach find s parameters that allow significant squeezing in the high-temperature regi me.\nThis extends the range of experimental setups in which non-classical correlations could be generated beyond the region of high quantum cooperat ivity.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/64/ END:VEVENT BEGIN:VEVENT SUMMARY:Christopher Baker\; Swati Singh\; (University of Queensland\; Univ ersity of Delaware\;) DTSTART:20220406T130000Z DTEND:20220406T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/67 DESCRIPTION:Title: Superfluid Optomechanics: Optomechanics with superfluid he lium films & Searching for dark matter and dark energy with mechanical sys tems\nby Christopher Baker\; Swati Singh\; (University of Queensland\; University of Delaware\;) as part of UniKORN seminars\n\n\nAbstract\nEarl y Career Researcher talk by Christopher Baker -\nTitle: Optomechanics with superfluid helium films\n\nAbstract: Cavity optomechanics focuses on the interaction between confined light and a mechanical degree of freedom. Vib rational modes of superfluid helium-4 are an attractive mechanical elemen t for cavity optomechanics\, thanks to their low dissipation arising from superfluid’s viscosity-free flow. Our approach to superfluid optomechan ics is based on nanometer-thick films of superfluid helium which self-ass emble on the surface of a microscale optical resonator inside a cryostat. Excitations within the film\, known as third sound\, manifest as surface thickness waves with a restoring force provided by the van der Waals inter action. These excitations\, by changing the amount of superfluid in the op tical mode’s evanescent field\, modulate the effective path length of th e optical cavity\, thereby providing a dispersive coupling between the sup erfluid motion and the light confined inside the optical resonator.\n\nLev eraging this optomechanical coupling mechanism\, we have previously shown laser-cooling and amplification of the superfluid thermal motion [1]\, obs ervation of quantized vortex dynamics in a superfluid helium film [2]\, as well as highly efficient Brillouin lasers [3]. In this talk\, I will give a rapid overview of our experimental platform\, and present recent develo pments where we optimize the superfluid fountain-pressure interaction to p rovide strong dynamical backaction. With this\, we show optically-driven r egenerative oscillation of a 7 mg effective mass superfluid acoustic mode\ , with a phonon lasing threshold power of only 3 pW\, corresponding to les s than one intracavity photon [4]. I will also show how this superfluid fu nctionality can be packaged into an alignment-free\, plug-and-play package requiring only fiber-optic access in a conventional cryostat\, through th e use of silicon-on-insulator photonic circuits.\n\n[1] G. Harris\, et al. \, Nature Physics 12 788 (2016).\n\n[2] Y. Sachkou et al.\, Science 366 64 72 (2019) \; S. Forstner et al\, New J. Phys 21 053029 (2019)\n\n[3] X. He \, et al\, Nature Physics\, 16 4 (2020) \; G. Harris\, et al.\, Opt. Expre ss 28 22450 (2020). [4] A. Sawadsky et al\, in preparation\, (2022) \; W. Wasserman et al\, in preparation\, (2022)\n\n----------------------------- --------------------------------------------------------------\n\nIntroduc tory talk by Swati Singh -\nTitle: Searching for dark matter and dark ener gy with mechanical systems\n\nAbstract: The coupling of normal\, Standard Model matter with dark matter or dark energy sometimes manifests itself as a mechanical effect: strain\, recoil kicks\, or acceleration. Following a review of the expected mechanical signature\, I will discuss the feasibil ity of searching for ultralight dark matter using various optomechanical s ystems\, highlighting the unique advantages of superfluid-based optomechan ical systems. I will also show that current mechanical systems have the se nsitivity to set new constraints on scalar field candidates for dark energ y. Finally\, I will briefly overview the promise of quantum noise limited detectors in the search for beyond the standard model physics.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/67/ END:VEVENT BEGIN:VEVENT SUMMARY:Xavier Rojas\; John Davis\; (Royal Holloway\, University of London \; University of Alberta\;) DTSTART:20220413T140000Z DTEND:20220413T150000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/68 DESCRIPTION:Title: Superfluid Optomechanics with Phononic Nanostructures & S uperfluid Helium Electromechanics\nby Xavier Rojas\; John Davis\; (Roy al Holloway\, University of London\; University of Alberta\;) as part of U niKORN seminars\n\n\nAbstract\nTalk 1- Xavier Rojas\n\nTitle: Superfluid O ptomechanics with Phononic Nanostructures\n\nAbstract: In quantum optomec hanics\, finding materials and strategies to limit losses has been crucial to the progress of the field. Recently\, superfluid 4He was proposed as a promising mechanical element for quantum optomechanics. This quantum flui d shows highly desirable properties (e.g.\, extremely low acoustic loss) f or a quantum optomechanical system. In current implementations\, superflui d optomechanical systems suffer from external sources of loss\, which spoi ls the quality factor of resonators. In this work1\, we propose an alterna te implementation\, exploiting nanofluidic confinement. Our approach\, bas ed on acoustic resonators formed within phononic nanostructures\, aims at limiting radiation losses to preserve the intrinsic properties of superflu id 4He. Using recent theory\, we derive the expected quality factors for a coustic resonators in different thermodynamic conditions. We calculate the sources of loss induced by the phononic nanostructures with numerical sim ulations. Our results indicate the feasibility of the proposed approach in a broad range of parameters\, which opens prospects for more complex geom etries.\n\n------------------------------------------------------------\n\ nTalk 2- John Davis\n\nTitle: Superfluid Helium Electromechanics \n\nAbstr act: Liquid helium possess many properties that make it an attractive medi um for studies of mechanical systems in the quantum regime\, such as low m echanical and dielectric losses. The flip side of this is to imagine usin g optomechanics or electromechanics to revisit the novel physics of superf luid helium\, including bosonic helium-4 and fermionic helium-3. In parti cular\, when spatially restricted in one dimension\, helium superfluids ar e expected to demonstrate quasi-two dimensional behavior with qualitativel y different physics than in three dimensions. By using nanofabrication te chniques to both confine the helium and provide an electromechanical detec tion scheme\, we are beginning the journey of studying such two-dimensiona l superfluids.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/68/ END:VEVENT BEGIN:VEVENT SUMMARY:Martin Frimmer\, Alexander Eichler (ETH Zurich) DTSTART:20220518T130000Z DTEND:20220518T140000Z DTSTAMP:20260404T111329Z UID:UniKORNseminars/69 DESCRIPTION:Title: Parametron optomechanics\nby Martin Frimmer\, Alexande r Eichler (ETH Zurich) as part of UniKORN seminars\n\n\nAbstract\nTALK 1 A BSTRACT:\n\nTitle: Optically levitated parametric oscillators\n\nAbstract: The center-of-mass degrees of freedom of an optically levitated nanoparti cle represent harmonic oscillators which lend themselves to studying and e xploiting the effects of parametric modulation. We discuss the parametric coupling between two such oscillation modes and its formal connection to t he physics of a quantum mechanical two-level system. Furthermore\, we intr oduce the parametron\, an oscillator-based logic element\, implemented wit h a levitated oscillator. We introduce different schemes for switching the parametron’s logical state and discuss limitations of speed and fidelit y.\n\n-----------------\n\nTALK 2 ABSTRACT:\n\nTitle: Building Ising machi nes from coupled parametric oscillators\n\nKerr parametric resonators\, or simply parametrons\, are driven nonlinear systems whose stable solutions can\, to some approximation\, be mapped to the two polarization states (up /down) of a spin. Networks of coupled parametrons are being studied as a w ay to find the ground state of Ising Hamiltonians through simulation\, and beyond that for artificial neural networks. However\, coupled nonlinear o scillators exhibit phenomena beyond those of a real spin system\, and offe r themselves as a fascinating system to study new physics. In this seminar \, we will understand the complex phase diagram that unfolds even in the ( seemingly) simple case of a two-parametron network. I will offer my person al outlook towards building Ising simulation machines from parametrons\, a nd how this ambitious endeavor may succeed in spite of considerable challe nges.\n LOCATION:https://stable.researchseminars.org/talk/UniKORNseminars/69/ END:VEVENT END:VCALENDAR