BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Vidya Madhavan (University of Illinois Urbana-Champaign) DTSTART:20200513T173000Z DTEND:20200513T183000Z DTSTAMP:20260404T110956Z UID:LongRangeColloquium/1 DESCRIPTION:Title: Microscopic evidence for a chiral superconducting order parameter in the heavy fermion superconductor $\\textrm{UTe}_2$\nby V idya Madhavan (University of Illinois Urbana-Champaign) as part of Long ra nge colloquium\n\n\nAbstract\nSpin-triplet superconductivity is a condensa te of electron pairs with spin-1 and an odd-parity wavefunction. A particu larly interesting manifestation of triplet pairing is a chiral p-wave stat e which is topologically non-trivial and a natural platform for realizing Majorana edge modes. Triplet pairing is however rare in solid state system s. The best-known example of chiral spin-triplet paring is the superfluid 3He-A phase and over the last few decades\, there has been an intensive se arch for potential spin-triplet superconductors in solid-state systems. Si nce pairing is most naturally mediated by ferromagnetic spin fluctuations\ , uranium based heavy fermion systems containing f-electron elements that can harbor both strong correlations and magnetism are considered ideal can didate spin-triplet superconductors. In this work I will present scanning tunneling microscopy (STM) data on the newly discovered heavy fermion supe rconductor\, $\\textrm{UTe}_2$ with a $T_{\\textrm{SC}}$ of 1.6K. I will s how signatures of coexisting Kondo effect and superconductivity which show competing spatial modulations within one unit-cell. STM spectroscopy at step edges show signatures of chiral in-gap states\, predicted to exist at the boundaries of a topological superconductor. Combined with existing da ta indicating triplet pairing\, the presence of chiral edge states suggest s that UTe2 is a strong candidate material for chiral-triplet topological superconductivity.\n LOCATION:https://stable.researchseminars.org/talk/LongRangeColloquium/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Nicola Spaldin (ETH Zürich) DTSTART:20200527T173000Z DTEND:20200527T183000Z DTSTAMP:20260404T110956Z UID:LongRangeColloquium/2 DESCRIPTION:Title: From materials to cosmology: Studying the early univers e under the microscope\nby Nicola Spaldin (ETH Zürich) as part of Lon g range colloquium\n\n\nAbstract\nUncovering the behavior of the early uni verse just after the Big Bang is an intriguing fundamental activity that i s extraordinarily difficult because of insurmountable issues associated wi th replaying the Big Bang in the laboratory. One route to the answer -- wh ich lies at the intersection between cosmology and materials science -- is to use laboratory materials to test the laws proposed for the formation o f defects such as cosmic strings in the early universe. Here I will show t hat a popular multiferroic material\, hexagonal yttrium manganite -- with its coexisting magnetic\, ferroelectric and structural phase transitions - - generates the crystallographic equivalent of cosmic strings. I will desc ribe how straightforward solution of the Schroedinger equation for yttrium manganite allows the important features of its behavior to be identified and quantified\, and present experimental results of what seem to be the f irst unambiguous demonstration of the expected cosmological scaling laws i n a real material. I will end with a plea for help with imaging the multif erroic "cosmic strings"\, and show some recent data suggesting that things might be less unambiguous than they seem.\n LOCATION:https://stable.researchseminars.org/talk/LongRangeColloquium/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Klaus Mølmer (Aarhus University) DTSTART:20200610T173000Z DTEND:20200610T183000Z DTSTAMP:20260404T110956Z UID:LongRangeColloquium/3 DESCRIPTION:Title: Quantum interactions with pulses of radiation\nby K laus Mølmer (Aarhus University) as part of Long range colloquium\n\n\nAbs tract\nHow does a quantum system interact with a travelling pulse of quant um radiation\, prepared for example in a number state or a coherent state of light? While crucial for multiple effects in quantum optics and for the entire concept of flying and stationary qubits\, quantum optics textbooks do not provide a formal description of this foundational and elementary i nteraction process. In this lecture\, I shall introduce a new (and simple) master equation that describes the joint quantum state of travelling puls es of quantized radiation and local quantum systems. Applications of the t heory will be presented for recent experiments with qubits and non-linear resonators interacting with pulses of optical\, microwave and acoustic rad iation.\n LOCATION:https://stable.researchseminars.org/talk/LongRangeColloquium/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Ali Yazdani (Princeton University) DTSTART:20200624T173000Z DTEND:20200624T183000Z DTSTAMP:20260404T110956Z UID:LongRangeColloquium/4 DESCRIPTION:by Ali Yazdani (Princeton University) as part of Long range co lloquium\n\nAbstract: TBA\n LOCATION:https://stable.researchseminars.org/talk/LongRangeColloquium/4/ END:VEVENT END:VCALENDAR