BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:William Witczak-Krempa (Université de Montréal) DTSTART:20200930T193000Z DTEND:20200930T203000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/1 DESCRIPTION:Title: Conformal field theories and quantum phase transitions: an entanglem ent perspective\nby William Witczak-Krempa (Université de Montréal) as part of quanTA Seminar\n\n\nAbstract\nQuantum phase transitions occur w hen a quantum system undergoes a sharp change in its ground state\, e.g. b etween a ferro- and para-magnet. I will present a remarkable set of transi tions\, called quantum critical\, that are described by conformal field th eories (CFTs). I will focus on 2 and 3 spatial dimensions\, where the conf ormal symmetry is powerful yet less constraining than in 1 dimension. We w ill probe these scale-invariant theories via the structure of their quantu m entanglement. The methods will include large-N expansions\, the AdS/CFT duality from string theory\, and large-scale numerical simulations. Finall y\, we’ll see that certain quantum Hall states\, which are topological i n nature\, possess very similar entanglement properties. This hints at bro ader principles that relate very different quantum states.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Monica Jinwoo Kang (Caltech) DTSTART:20201104T213000Z DTEND:20201104T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/2 DESCRIPTION:Title: The infinite HaPPY code\nby Monica Jinwoo Kang (Caltech) as part of quanTA Seminar\n\n\nAbstract\nI will construct an infinite-dimensional analog of the HaPPY code as a growing series of stabilizer codes defined respective to their Hilbert spaces. These Hilbert spaces are related by is ometries that will be defined during this talk. I will analyze its system in various aspects and discuss its implications in AdS/CFT. Our result hin ts that the relevance of quantum error correction in quantum gravity may n ot be limited to the CFT context.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Anton Kapustin (Caltech) DTSTART:20201209T203000Z DTEND:20201209T213000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/3 DESCRIPTION:Title: The topology and geometry of the space of gapped lattice systems \nby Anton Kapustin (Caltech) as part of quanTA Seminar\n\n\nAbstract\nRec ently there has been a lot of progress in classifying phases of gapped qua ntum many-body systems. From the mathematical viewpoint\, a phase of a qua ntum system is a connected component of the “space” of gapped quantum systems\, and it is natural to study the topology of this space. I will ex plain how to probe it using generalizations of the Berry curvature. I will focus on the case of lattice systems where all constructions can be made rigorous. Coarse geometry plays an important role in these constructions.\ n LOCATION:https://researchseminars.org/talk/quanTASeminar/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Karen Yeats (University of Waterloo) DTSTART:20210122T213000Z DTEND:20210122T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/4 DESCRIPTION:Title: Combinatorial structures in perturbative quantum field theory\nb y Karen Yeats (University of Waterloo) as part of quanTA Seminar\n\n\nAbst ract\nI will give an overview of a few places where combinatorial structur es have an interesting role to play in quantum field theory and which I ha ve been involved in to varying degrees\, from the Connes-Kreimer Hopf alge bra and other renormalization Hopf algebras\, to the combinatorics of Dyso n-Schwinger equations and the graph theory of Feynman integrals.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Igor Boettcher (University of Alberta) DTSTART:20210317T203000Z DTEND:20210317T213000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/5 DESCRIPTION:Title: Crystallography of hyperbolic lattices: from children's drawings to Fuchsian groups\nby Igor Boettcher (University of Alberta) as part of quanTA Seminar\n\n\nAbstract\nHyperbolic lattices are tessellations of the hyperbolic plane using\, for instance\, heptagons or octagons. They are r elevant for quantum error correcting codes and experimental simulations of quantum physics in curved space. Underneath their perplexing beauty lies a hidden and\, perhaps\, unexpected periodicity that allows us to identify the unit cell and Bravais lattice for a given hyperbolic lattice. This pa ves the way for applying powerful concepts from solid state physics and\, potentially\, finding a generalization of Bloch's theorem to hyperbolic la ttices. In my talk\, I will explain some of the mathematics underlying thi s hyperbolic crystallography.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Maria Emelianenko (George Mason University) DTSTART:20210414T203000Z DTEND:20210414T213000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/6 DESCRIPTION:Title: Random walks and graphs in materials\, biology\, and quantum informa tion science\nby Maria Emelianenko (George Mason University) as part o f quanTA Seminar\n\n\nAbstract\nWhat does mathematics\, materials science\ , biology\, and quantum information science have in common? It turns out\, there are many connections worth exploring. I this talk\, I will focus on graphs and random walks\, starting from the classical mathematical constr ucts and moving on to quantum descriptions and applications. We will see h ow the notions of graph entropy and KL divergence appear in the context of characterizing polycrystalline material microstructures and predicting th eir performance under mechanical deformation\, while also allowing to meas ure adaptation in cancer networks and entanglement of quantum states. We w ill discover unified conditions under which master equations for classical random walks exhibit nonlocal and non-diffusive behavior and see how quan tum walks allow to realize the coveted exponential speedup in quantum Hami ltonian simulations. Recent classical and quantum breakthroughs and open q uestions will be discussed.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Jonas Fransson (Uppsala University) DTSTART:20220927T213000Z DTEND:20220927T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/7 DESCRIPTION:Title: A correlated view of chiral-induced spin selectivity\nby Jonas F ransson (Uppsala University) as part of quanTA Seminar\n\nLecture held in PHYS 103.\n\nAbstract\nChiral-induced spin selectivity is an intriguing ph enomenon that\, to our knowledge\, rests on a foundation of structural chi rality\, spin-orbit interactions\, and strongly nonequilibrium conditions. The effect is a measure of the response to changes in the magnetic enviro nment coupled to the active region\, and the phenomenology refers back to the experimental observations of substantial changes in the charge current amplitude through chiral molecules upon changes in the external magnetic conditions. Chiral-induced spin selectivity has been shown to not be limit ed to multistranded helical structures\, such as double-stranded DNA molec ules and bacteriorhodopsin\, but has also been observed in\, for example\, various types of peptides and polyalanines and\, recently\, also in helic ene.\n\nIn order to depart from the generic single electron\, or\, non-int eracting models that have\, quite unsuccessfully\, been used in attempts t o describe the chiral-induced spin selectivity effect\, it is proposes to include many-body effects\, arising from\, e.g.\, electron-electron or ele ctron-vibron interactions. In cooperation with spin-orbit interactions\, t he many-body interactions generate exchange splitting between the spin cha nnels which is viable for the chiral-induced spin selectivity phenomenon. By constructing models comprising either electron-electron or electron-vib ron interactions\, it can be demonstrated that the chiral-induced spin sel ectivity effect increases by several orders of magnitude compared to the r esults from any non-interacting description. The phenomenology of the chir al-induced spin selectivity effect indicates that charge transfer within t he chiral molecule is accompanied by the emergence of intra-molecular spin -polarization.\n\n \n\n \n\nSome relevant references:\n\n \n\nJ. Fransson\ , Chirality induced spin-selectivity: The role of electron correlation: J Phys Chem Lett\, 10\, 7126 (2019).\n\nJ. Fransson\, Vibrational origin of exchange splitting and chiral-induced spin selectivity: Phys Rev B\, 102\, 235416 (2020).\n\nJ. Fransson\, Charge Redistribution and Spin Polarizati on Driven by Correlation Induced Electron Exchange in Chiral Molecules: Na no Lett\, 21\, 3026 (2021).\n\nJ. Fransson\, Charge and Spin Dynamics and Enantioselectivity in Chiral Molecules: J Phys Chem Lett\, 13\, 808 (2022) .\n\nIn-person only on University of Saskatchewan campus in room PHYS 103. \n LOCATION:https://researchseminars.org/talk/quanTASeminar/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Gordon Sarty (University of Saskatchewan) DTSTART:20230124T213000Z DTEND:20230124T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/8 DESCRIPTION:Title: MRI as an example of quantum engineering\nby Gordon Sarty (Unive rsity of Saskatchewan) as part of quanTA Seminar\n\nLecture held in PHYSIC S 103.\n\nAbstract\nThe term quantum engineering generally focuses around the design of quantum computers\, but MRI is an excellent example of quant um mechanics applied to engineering. It works by exciting proton spins in water molecules in a patient's body\, spatially encoding them by phase acc ording to systematic applications of RF pulses and magnetic field configur ations. The engineering needed is both old and new. On one hand\, an appli cation of simple Ham radio technology is used to make the small MRI protot ypes now in my lab. This direction will hopefully lead to a proliferation of MRIs to nearly every medical clinic situation around the world. On the other hand\, the use of new quantum materials - which is definitely not Ha m radio technology - promises MRI designs that are ever smaller\, conceptu ally different in function and more sensitive. In this lecture\, I will ta lk about both the small simple MRIs that I am building now and about the w ork we have been doing with diamonds as a quantum material to serve as ver y sensitive magnetometers for application to future MRI designs.\n\nHybrid delivery (in person on University of Saskatchewan campus and via Zoom).\n LOCATION:https://researchseminars.org/talk/quanTASeminar/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Artur Sowa (University of Saskatchewan) DTSTART:20220125T213000Z DTEND:20220125T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/9 DESCRIPTION:Title: New application of harmonic analysis to quantum theory and engineeri ng\nby Artur Sowa (University of Saskatchewan) as part of quanTA Semin ar\n\n\nAbstract\nHarmonic analysis has played a foundational role in quan tum theory all throughout its historical development.\nTo recall a few wel l-known examples\, it is expressly present in the Heisenberg uncertainty p rinciple (1920s)\; it\nwas fundamental in solving the quantum spin chain ( 1970s)\; it now helps to gain insights into the problem of\nquantumness in relation to quantum computing (2010s). While sourcing some of its methods from the repertoire\nof harmonic analysis\, Physics has always generously paid back\, e.g.\, the coherent state theory stimulated the\ndevelopment of wavelet techniques and of the linear canonical transform. In this talk I will highlight some\nlesser-known recent examples of quantum application s of harmonic analysis. In particular\, I will demonstrate\nhow the Haar t ransform (i.e.\, a special type of wavelet transform) helps to analyze the dynamics of an array of\nqubits. I will also highlight applications of th e generalized Fourier transform on the multiplicative group of\npositive r ationals (i.e.\, the group furnished by the multiplication of common fract ions) to the analysis of arrays\nof bosons. The ultimate purpose of this w ork is to help countervail the so-called “curse of dimensionality”\nwh ich arises in quantum engineering and other aspects of quantum theory and modelling. The outcomes that I\nwill relay serve as good examples of value being added (and multiplied) when mathematicians and physicists\nexchange ideas. The tools that were inspired by these collaborative efforts help t ackle more general problems of\noperator analysis. They also highlight som e mesmerizing new connections between quantum theory and the\nanalytic num ber theory as well as fractals.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Steven Rayan (University of Saskatchewan) DTSTART:20220215T213000Z DTEND:20220215T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/10 DESCRIPTION:Title: New models of quantum matter inspired by geometry\nby Steven Ra yan (University of Saskatchewan) as part of quanTA Seminar\n\nLecture held in PHYS 103.\n\nAbstract\nThe exciting and rapidly-growing field of topol ogical materials has brought with it unexpected new connections\nbetween p hysics and mathematics. As the name suggests\, topology has played a signi ficant role in\nunderstanding and classifying these materials. In this tal k\, I will offer a brief look at another emerging chapter\nin this story i n which exotic geometries — of the kind found in the woodcuts of M.C. Es cher! — anticipate new\nmodels of two-dimensional quantum matter associa ted with hyperbolic lattices.\n\nIn-person only on University of Saskatche wan campus in room PHYS 103.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Matthew Rupert (University of Saskatchewan) DTSTART:20230306T220000Z DTEND:20230306T233000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/11 DESCRIPTION:Title: Recent progress on the Kazhdan-Lusztig correspondence for vertex op erator algebras and quantum groups\nby Matthew Rupert (University of S askatchewan) as part of quanTA Seminar\n\nLecture held in PHYSICS 126.\n\n Abstract\nVertex operator algebras are the symmetry algebras of two dimens ional conformal field theory. In a famous series of papers\, Kazhdan and L usztig proved an equivalence between particular semi-simple categories of modules over affine Lie algebras and quantum groups\, the former of which can also be realized as modules over a corresponding vertex operator algeb ra. Such equivalences between representation categories of vertex operator algebras and quantum groups are now broadly referred to as the Kazhdan-Lu sztig correspondence.\n\nThere has been substantial research interest over the last two decades in understanding the Kazhdan-Lusztig correspondence for vertex operator algebras with non semi-simple representation theory. I n this talk I will present recent categorical results which aid in proving such equivalences with applications to the singlet vertex algebra in part icular. Based on joint work with Thomas Creutzig and Simon Lentner.\n\nTal k is hybrid with in-person audience in room PHYSICS 126 on the University of Saskatchewan campus with a simultaneous virtual stream on Zoom.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Thomas Chen (UT Austin) DTSTART:20230310T203000Z DTEND:20230310T213000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/12 DESCRIPTION:Title: On the emergence of Boltzmann equations from quantum dynamics\n by Thomas Chen (UT Austin) as part of quanTA Seminar\n\n\nAbstract\nThe ma thematically rigorous derivation of nonlinear Boltzmann equations from fir st principles in interacting physical systems is an extremely active resea rch area in Analysis\, Mathematical Physics\, and Applied Mathematics. In classical physical systems\, rigorous results of this type have been obtai ned for some models. In the quantum case on the other hand\, the problem h as essentially remained open. In this talk\, I will explain how a cubic qu antum Boltzmann equation arises within the fluctuation dynamics around a B ose-Einstein condensate\, within the quantum field theoretic description o f an interacting Boson gas. This is based on joint work with Michael Hott. \n\nVirtual talk held in conjunction with the Mathematics & Statistics Col loquium at the University of Saskatchewan.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Sean Lawton (George Mason University) DTSTART:20230712T203000Z DTEND:20230712T214500Z DTSTAMP:20260422T214305Z UID:quanTASeminar/13 DESCRIPTION:Title: What is a character variety?\nby Sean Lawton (George Mason Univ ersity) as part of quanTA Seminar\n\nLecture held in St. Thomas More 1002. \n\nAbstract\nCharacter varieties are topological spaces that are a playgr ound for intermingling areas of mathematics and science. In this talk\, I will give a definition that unifies many approaches to them\, discuss are as of study where they naturally arise\, and give examples requiring littl e more than linear algebra to understand. There will be pictures.\n\nIn-p erson only on University of Saskatchewan campus in room St. Thomas More 10 02.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Lindsay LeBlanc (University of Alberta) DTSTART:20231128T213000Z DTEND:20231128T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/14 DESCRIPTION:Title: Light-matter interactions in cold and ultracold neutral atomic gase s: applications to quantum technologies\nby Lindsay LeBlanc (Universit y of Alberta) as part of quanTA Seminar\n\nLecture held in PHYSICS 103.\n\ nAbstract\nNeutral atomic gases provide fantastic opportunities for studyi ng and controlling quantum phenomena\, ranging from many-body physics to q uantum computers. In our research\, we use the well-known interactions bet ween cold gases and electromagnetic radiation to harness various quantum d egrees of freedom. Quantum memories\, used for storing and manipulating ph otonic signals\, will be a key component in quantum communications systems \, especially in realizing critical quantum repeater infrastructure. Cold atoms have significant potential as high performance spin-wave quantum mem ories\, due to the long storage times associated with low temperature and slow thermal diffusion. In our work\, we demonstrate two memory protocols in ultracold (sometimes Bose-condensed) atoms\, which hold the potential f or high-performance light storage: the Autler-Townes splitting (ATS) and s uperradiant approaches. These methods provide a path towards practical imp lementations in both ground- and satellite-based quantum communications sy stems\, and we are working on both increasing performance and developing p ractical implementations. In a other directions\, our lab also uses ultrac old ensembles to study unconventional quantum gates for quantum computing\ , and warm vapours in microwave cavities to exploit simultaneous microwave and optical transitions.\n\nIn-person only on University of Saskatchewan campus in room PHYSICS 103.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Mao Yoshii (Tokyo University) DTSTART:20240312T213000Z DTEND:20240312T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/15 DESCRIPTION:Title: Invitation to heterolayer systems: towards an extension to the supe rconducting phase\nby Mao Yoshii (Tokyo University) as part of quanTA Seminar\n\nLecture held in PHYSICS 103.\n\nAbstract\nIt has been almost 20 years since the exfoliation technique for graphene was developed at the b eginning of this century. Various two-dimensional materials can now be pro duced and their properties have been investigated. These thin films exhibi t different properties from their original three-dimensional counterpart\, but we can also create new systems by stacking them. In particular\, in r ecent years\, the discovery of unconventional superconductivity in magic-a ngle twisted bilayer graphene and the improvement of fabrication technique s of multilayer systems have increased attention to the superconducting st ate of heterolayer systems. On the other hand\, thin-film multilayer syste ms are generally quasiperiodic and this makes theoretical studies difficul t. For noninteracting systems\, we have the so-called Brillouin Zone (BZ) folding method which helps us to study multilayer systems efficiently. How ever\, this method has not been extended to interacting systems. In this t alk\, we will start with a review of the BZ folding method for normal-cond ucting phases and then extend it to superconducting phases.\n\nIn-person o nly on University of Saskatchewan campus in room PHYSICS 103.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Christopher Mahadeo (University of Illinois at Chicago) DTSTART:20240213T213000Z DTEND:20240213T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/16 DESCRIPTION:Title: Something old\, something new\, something borrowed\, and something quantized\nby Christopher Mahadeo (University of Illinois at Chicago) as part of quanTA Seminar\n\nLecture held in PHYSICS 103.\n\nAbstract\nRec ent work by the quanTA center has pioneered the idea of hyperbolic band th eory\, the mathematical formulation of a new class of quantum materials. I n this talk I will discuss how new approaches to classical band theory led to this development\, and how techniques borrowed from random matrix theo ry have the potential to produce fascinating results.\n\nIn-person only on University of Saskatchewan campus in room PHYSICS 103.\n LOCATION:https://researchseminars.org/talk/quanTASeminar/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Barry Sanders (University of Calgary) DTSTART:20240206T213000Z DTEND:20240206T223000Z DTSTAMP:20260422T214305Z UID:quanTASeminar/17 DESCRIPTION:Title: Kittens\, cats\, and compasses: superposing coherent states for qua ntum sensing\, quantum communication\, quantum computing\, and quantum fun \nby Barry Sanders (University of Calgary) as part of quanTA Seminar\n \nLecture held in PHYSICS 103.\n\nAbstract\nGlauber coherent states are se miclassical in the sense that that follow classical harmonic-oscillator dy namics and are minimum-uncertainty states. A superposition of two macrosco pically distinct coherent states is a Schrödinger cat state (alive and de ad in superposition) and a kitten if not macroscopically distinct. Superpo sing two- and multi-mode coherent states is an entangled coherent state. G eometric intuition arises through quasiprobability representations\, allow ing us to talk about superposing coherent states on a line (relevant to bo sonic qubits) and on a circle (e.g.\, compass states also relevant to boso nic qubits). I present this potted history followed by our proposal for ma king a nuclear cat state: arXiv:2304.13813.\n\nIn-person on University of Saskatchewan campus in room PHYSICS 103. (Zoom link reserved for USask gra duate students who are based off-site or who otherwise cannot attend in pe rson.)\n LOCATION:https://researchseminars.org/talk/quanTASeminar/17/ END:VEVENT END:VCALENDAR