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:20260422T225927Z UID:LongRangeColloquium/1 DESCRIPTION:Title: Microscopic evidence for a chiral superconducting order parame ter in the heavy fermion superconductor $\\textrm{UTe}_2$\nby Vidya Ma dhavan (University of Illinois Urbana-Champaign) as part of Long range col loquium\n\n\nAbstract\nSpin-triplet superconductivity is a condensate of e lectron pairs with spin-1 and an odd-parity wavefunction. A particularly i nteresting manifestation of triplet pairing is a chiral p-wave state which is topologically non-trivial and a natural platform for realizing Majoran a edge modes. Triplet pairing is however rare in solid state systems. The best-known example of chiral spin-triplet paring is the superfluid 3He-A p hase and over the last few decades\, there has been an intensive search fo r potential spin-triplet superconductors in solid-state systems. Since pai ring is most naturally mediated by ferromagnetic spin fluctuations\, urani um based heavy fermion systems containing f-electron elements that can har bor both strong correlations and magnetism are considered ideal candidate spin-triplet superconductors. In this work I will present scanning tunneli ng microscopy (STM) data on the newly discovered heavy fermion superconduc tor\, $\\textrm{UTe}_2$ with a $T_{\\textrm{SC}}$ of 1.6K. I will show sig natures of coexisting Kondo effect and superconductivity which show compet ing spatial modulations within one unit-cell. STM spectroscopy at step ed ges show signatures of chiral in-gap states\, predicted to exist at the bo undaries of a topological superconductor. Combined with existing data indi cating triplet pairing\, the presence of chiral edge states suggests that UTe2 is a strong candidate material for chiral-triplet topological superco nductivity.\n LOCATION:https://researchseminars.org/talk/LongRangeColloquium/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Nicola Spaldin (ETH Zürich) DTSTART:20200527T173000Z DTEND:20200527T183000Z DTSTAMP:20260422T225927Z UID:LongRangeColloquium/2 DESCRIPTION:Title: From materials to cosmology: Studying the early universe under the microscope\nby Nicola Spaldin (ETH Zürich) as part of Long range colloquium\n\n\nAbstract\nUncovering the behavior of the early universe j ust after the Big Bang is an intriguing fundamental activity that is extra ordinarily difficult because of insurmountable issues associated with repl aying the Big Bang in the laboratory. One route to the answer -- which lie s at the intersection between cosmology and materials science -- is to use laboratory materials to test the laws proposed for the formation of defec ts such as cosmic strings in the early universe. Here I will show that a p opular multiferroic material\, hexagonal yttrium manganite -- with its coe xisting magnetic\, ferroelectric and structural phase transitions -- gener ates the crystallographic equivalent of cosmic strings. I will describe ho w straightforward solution of the Schroedinger equation for yttrium mangan ite allows the important features of its behavior to be identified and qua ntified\, and present experimental results of what seem to be the first un ambiguous demonstration of the expected cosmological scaling laws in a rea l material. I will end with a plea for help with imaging the multiferroic "cosmic strings"\, and show some recent data suggesting that things might be less unambiguous than they seem.\n LOCATION:https://researchseminars.org/talk/LongRangeColloquium/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Klaus Mølmer (Aarhus University) DTSTART:20200610T173000Z DTEND:20200610T183000Z DTSTAMP:20260422T225927Z UID:LongRangeColloquium/3 DESCRIPTION:Title: Quantum interactions with pulses of radiation\nby Klaus M ølmer (Aarhus University) as part of Long range colloquium\n\n\nAbstract\ nHow does a quantum system interact with a travelling pulse of quantum rad iation\, prepared for example in a number state or a coherent state of lig ht? While crucial for multiple effects in quantum optics and for the entir e concept of flying and stationary qubits\, quantum optics textbooks do no t provide a formal description of this foundational and elementary interac tion process. In this lecture\, I shall introduce a new (and simple) maste r equation that describes the joint quantum state of travelling pulses of quantized radiation and local quantum systems. Applications of the theory will be presented for recent experiments with qubits and non-linear resona tors interacting with pulses of optical\, microwave and acoustic radiation .\n LOCATION:https://researchseminars.org/talk/LongRangeColloquium/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Ali Yazdani (Princeton University) DTSTART:20200624T173000Z DTEND:20200624T183000Z DTSTAMP:20260422T225927Z UID:LongRangeColloquium/4 DESCRIPTION:by Ali Yazdani (Princeton University) as part of Long range co lloquium\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/LongRangeColloquium/4/ END:VEVENT END:VCALENDAR