COVID-19 information for PI Residents and Visitors
David Huse, Princeton University
Young Lee, Massachusetts Institute of Technology
Steve Kivelson, Stanford University
Radu Coldea, University of Oxford
Paul Chaikin, New York University
Patrick Lee, Massachusetts Institute of Technology
Seamus Davvis, Cornell University
Eduardo Fradkin, University of Illinois at Urbana-Champaign
Leon Balents, Kavli Institute for Theoretical Physics
Keynote Speakers:
- Bob Cava, Princeton University
- Allan MacDonald, University of Texas at Austin
Speakers:
- Bruce Gaulin, McMaster University
- David Hawthorn, University of Waterloo
- Yong-Baek Kim, University of Toronto
- Sung-Sik Lee, Perimeter Institute & McMaster University
- Graeme Luke, McMaster University
- Volodya Miransky, University of Western Ontario
- Arun Paramekanti, University of Toronto
- Andrew Achkar, University of Waterloo
- Peter Barfuss, University of Waterloo
- Ganapathy Baskaran, Institute of Mathematical Sciences Chennai
- Grigory Bednik, University of Waterloo
- Anton Burkov, University of Waterloo
- Juan Carrasquilla Alvarez, Perimeter Institute
- Hilary Carteret, Perimeter Institute
- Bob Cava, Princeton University
- Denis Dalidovich, Perimeter Institute
- Bruce Gaulin, McMaster University
- John Greedan, McMaster University
- David Hawthorn, University of Waterloo
- Chris Herdman, University of Waterloo
- Ciaran Hickey, University of Toronto
- Robert Hill, University of Waterloo
- Wen Huang, McMaster University
- Emy Illes, University of Guelph
- Stephen Julian, University of Toronto
- Yong-Baek Kim, University of Toronto
- Holger Kleinke, University of Waterloo
- Bohdan Kulchytskyy, University of Waterloo
- Jan Kycia, University of Waterloo
- Stephen Kycia, University of Guelph
- Patrick Lafleur, Trent University
- Sung-Sik Lee, Perimeter Institute & McMaster University
- Graeme Luke, McMaster University
- Peter Lunts, Perimeter Institute
- Qianli Ma, University of Waterloo
- Allan MacDonald, University of Texas at Austin
- Joseph Macoejko, University of Alberta
- John Malcolm, University of Guelph
- Christopher McMahon, University of Waterloo
- Casey Marjerrison, McMaster University
- Jia-Wei Mei, Perimeter Institute
- Volodya Miransky, University of Western Ontario
- Chris Mitchelitis, University of Waterloo
- Tim Munsie, McMaster University
- Elisabeth Nicol, University of Guelph
- Thomas O'Brien, Perimeter Institute
- Ivan Panifilov, University of Waterloo
- Arun Paramekanti, University of Toronto
- Boris Pavlovic, University of Guelph
- David Pomaranski, University of Waterloo
- Sayeh Rajabi, University of Waterloo
- Amany Raslan, Trent University
- Jeff Rau, University of Waterloo
- Julian Rincon, Perimeter Institute
- Shouvik Sur, McMaster University
- William Toews, University of Waterloo
- Giacomo Torlai, University of Waterloo
- Guifre Vidal, Perimeter Institute
- Murray Wilson, McMaster University
- William Witczak-Krempa, Perimeter Institute
- Rachel Wortis, Trent University
- Wei Zheng, Perimeter Institute
- An Zhou, Perimeter Institute
Time |
Event |
Location |
9:00 – 9:55 |
Registration and Coffee |
Atrium |
9:55 – 10:00 |
Jan Kycia, University of Waterloo |
Lazaridis Theatre |
10:00 – 11:00 |
Allan MacDonald, University of Texas at Austin |
Lazaridis Theatre |
11:00 – 11:30 |
Graeme Luke, McMaster University |
Lazaridis Theatre |
11:30 – 12:00 |
Arun Paramekanti, University of Toronto |
Lazaridis Theatre |
12:00 – 12:10 |
Conference Photo |
TBA |
12:10 – 1:30 |
Lunch |
Bistro 2nd Floor |
1:30 – 2:30 |
Bob Cava, Princeton University |
Lazaridis Theatre |
2:30 – 3:00 |
Volodya Miransky, University of Western Ontario |
Lazaridis Theatre |
3:00 – 3:30 |
Sung-Sik Lee, Perimeter Institute & McMaster University |
Lazaridis Theatre |
3:30 – 4:00 |
Afternoon Coffee Break |
Bistro 1st Floor |
4:00 – 4:30 |
David Hawthorn, University of Waterloo |
Lazaridis Theatre |
4:30 – 5:00 |
Yong-Baek Kim, University of Toronto |
Lazaridis Theatre |
5:00 – 5:30 |
Bruce Gaulin, McMaster University |
Lazaridis Theatre |
5:30 |
Jan Kycia, University of Waterloo |
Lazaridis Theatre |
Bob Cava, Princeton University
Recent chemical and structural studies of geometrically frustrated magnets, Dirac Semimetals, and topological insulators.
Our search for new materials of (hopeful) relevance to materials physics is wide ranging. One of our primary interests is in finding new geometrically frustrated magnets and working on their structure-property relations. In this context in recent years we have found and grown crystals of a new class of pyrochlore magnets based on fluorine instead of oxygen. This chemical difference allows pyrochlores to be made with magnetic transition metals on the “B sites”, and non-magnetic ions on the A sites, which results in stronger magnetic coupling than is seen in the rare earth pyrochlores. This therefore provides the ability to probe magnetic frustration on the pyrochlore lattice at more easily accessible temperatures. Some of our initial work on these emergent materials, NaCaCo2F7 is an example of one of them, will be described. We have also been exploring the edges of the Dirac semimetal materials space and have recently gotten some interesting results on the Dirac semimetal superconductor Au2Pb. I will describe this material and a recent finding in Ca3P2, a material most often encountered in rat poison. Finally, if time permits, I will describe recent results in our search for the perfect topological insulator.
Bruce Gaulin, McMaster University
Quasi-Two Dimensional Spin and Phonon Excitations in High Tc related Quantum Magnets
New developments in time-of-flight neutron spectroscopy allow a remarkably comprehensive determination of the full spin and phonon excitation spectrum in many materials. I will discuss these new techniques and show results from the "214" family of layered quantum magnets - which are also the La(2-x)Ba/Sr(x)CuO4 high Tc superconductors. We observe the expected highly dispersive spin excitations emanating from the "pi-pi" magnetic zone centres, as well as a host of optic and acoustic phonons, and roughly speaking, the spin and phonon excitations separate as a function of momentum. However, a very interesting resonant phenomena is observed which is coincident with the low energy crossings of the dispersive spin excitations with the relatively dispersion less phonons.
David Hawthorn, University of Waterloo
Nematicity and charge density wave order in stripe ordered cuprates probed via resonant x-ray scattering
Akin to liquid crystals, electronic nematic phases have been theorized and observed in several correlated materials, including cuprate and pnictide superconductors. I will discuss how electronic nematicity is observed in stripe-ordered cuprates using resonant x-ray scattering and how it relates to structural distortions and charge-density wave order.
Yong-Baek Kim, University of Toronto
Topological and Broken-Symmetry Phases in Three-dimensional Hyperhoneycomb Iridates
Recently three-dimensional versions of honeycomb-lattice iridates, beta and gamma phases of Li2IrO3, have been discovered. It has been theoretically suggested that these hyperhoneycomb iridates may hold promise for the realization of the Kitaev spin liquid or the exactly solvable model for the elusive quantum spin liquid phase. Recent scattering experiments on these systems have, however, revealed highly non-trivial magnetic spiral phases. We propose a theory that may explain the emergence of this unusual magnetic order and discuss why the current experimental data may suggest that the hyperhoneycomb iridates are not too far from the Kitaev limit.
Sung-Sik Lee, Perimeter Institute & McMaster University
Low energy field theories for non-Fermi liquids
In this talk, I will discuss some of the recent progress made on low energy effective field theories for non-Fermi liquids. Based on a dimensional regularization scheme, physical properties of various non-Fermi liquid states can be computed in controlled ways. I will emphasize novel features that arise due to the interplay between interaction and the presence of extensive gapless modes near Fermi surface. The examples include non-analytic expansion in coupling, emergent locality and UV/IR mixing.
Graeme Luke, McMaster University
Muon Spin Rotation/Relaxation Studies of Unconventional Superconductivity
Muon spin rotation/relaxation is a powerful technique for studying unconventional superconductors, whose order parameter doesn't have the same symmetry as its host material's crystal structure. I will describe our work on Sr2RuO4, UPt3, CuxBi2Se3 and other topical systems, some of which exhibit broken time reversal symmetry in their superconducting states.
Allan MacDonald, University of Texas at Austin
The Quantum Hall Effect and Spintronics
A series of fundamental discoveries over the past thirty years has dramatically improved our ability to read, write, and process magnetically stored information. I will briefly review some of these advances before focusing on the recently discovered and particularly promising spin-orbit torques which act on the collective spin of thin film magnetic conductors when they are placed on a substrate with strong spin-orbit interactions. Spin-orbit torques are normally interpreted in terms of the spin Hall effect, spin-current that flows perpendicular to charge current in any conductor. The spin-Hall effect in the best spin-orbit torque materials is thought to have a large contribution from states away from the Fermi energy that is insensitive to disorder and therefore referred to as intrinsic. I will argue that the physics of the intrinsic spin Hall effect is quite closely related to the physics of the quantum Hall effect, and on this basis speculate on strategies to find the material combinations that optimize the spin-orbit torque effect.
Volodya Miransky, University of Western Ontario
Magnetized relativistic plasma as a Weyl metal
It has been recently established that a magnetized relativistic plasma yields an interesting example of a Weyl metal. I discuss the properties of magnetized relativistic plasma and its possible role in some astrophysics phenomena.
Arun Paramekanti, University of Toronto
Double perovskite materials: From Chern bands to unusual Mott insulators
Double perovskites, a class of oxide materials with 3d and 5d transition metal ions, can realize a wide variety of interesting phases. Here we focus on our recent theoretical work suggesting the appearance of Chern insulators, and possible emergent nematic phases at Chern transitions in such systems. We will also discuss Mott insulating double perovskites with iridium moments which appear to host unusual magnetic interactions on the 3-dimensional fcc lattice, and present comparisons with experimental data.
Quasi-Two Dimensional Spin and Phonon Excitations in High Tc related Quantum Magnets
New developments in time-of-flight neutron spectroscopy allow a remarkably comprehensive determination of the full spin and phonon excitation spectrum in many materials. I will discuss these new techniques and show results from the "214" family of layered quantum magnets - which are also the La(2-x)Ba/Sr(x)CuO4 high Tc superconductors. We observe the expected highly dispersive spin excitations emanating from the "pi-pi" magnetic zone centres, as well as a host of optic and acoustic phonons, and roughly speaking, the spin and phonon excitations separate as a function of momentum.
Topological and Broken-Symmetry Phases in Three-dimensional Hyperhoneycomb Iridates
Recently three-dimensional versions of honeycomb-lattice iridates, beta and gamma phases of Li2IrO3, have been discovered. It has been theoretically suggested that these hyperhoneycomb iridates may hold promise for the realization of the Kitaev spin liquid or the exactly solvable model for the elusive quantum spin liquid phase. Recent scattering experiments on these systems have, however, revealed highly non-trivial magnetic spiral phases.
Nematicity and charge density wave order in stripe ordered cuprates probed via resonant x-ray scattering
Akin to liquid crystals, electronic nematic phases have been theorized and observed in several correlated materials, including cuprate and pnictide superconductors. I will discuss how electronic nematicity is observed in stripe-ordered cuprates using resonant x-ray scattering and how it relates to structural distortions and charge-density wave order.
Low energy field theories for non-Fermi liquids
In this talk, I will discuss some of the recent progress made on low energy effective field theories for non-Fermi liquids. Based on a dimensional regularization scheme, physical properties of various non-Fermi liquid states can be computed in controlled ways. I will emphasize novel features that arise due to the interplay between interaction and the presence of extensive gapless modes near Fermi surface. The examples include non-analytic expansion in coupling, emergent locality and UV/IR mixing.
Magnetized relativistic plasma as a Weyl metal
It has been recently established that a magnetized relativistic plasma yields an interesting example of a Weyl metal. I discuss the properties of magnetized relativistic plasma and its possible role in some astrophysics phenomena.
Recent chemical and structural studies of geometrically frustrated magnets, Dirac Semimetals, and topological insulators.
Our search for new materials of (hopeful) relevance to materials physics is wide ranging. One of our primary interests is in finding new geometrically frustrated magnets and working on their structure-property relations. In this context in recent years we have found and grown crystals of a new class of pyrochlore magnets based on fluorine instead of oxygen. This chemical difference allows pyrochlores to be made with magnetic transition metals on the “B sites”, and non-magnetic ions on the A sites, which results in stronger magnetic coupling than is seen in the rare earth pyrochlores.
Double perovskite materials: From Chern bands to unusual Mott insulators
Double perovskites, a class of oxide materials with 3d and 5d transition metal ions, can realize a wide variety of interesting phases. Here we focus on our recent theoretical work suggesting the appearance of Chern insulators, and possible emergent nematic phases at Chern transitions in such systems. We will also discuss Mott insulating double perovskites with iridium moments which appear to host unusual magnetic interactions on the 3-dimensional fcc lattice, and present comparisons with experimental data.
Muon Spin Rotation/Relaxation Studies of Unconventional Superconductivity
Muon spin rotation/relaxation is a powerful technique for studying unconventional superconductors, whose order parameter doesn't have the same symmetry as its host material's crystal structure. I will describe our work on Sr2RuO4, UPt3, CuxBi2Se3 and other topical systems, some of which exhibit broken time reversal symmetry in their superconducting states.
The Quantum Hall Effect and Spintronics
A series of fundamental discoveries over the past thirty years has dramatically improved our ability to read, write, and process magnetically stored information. I will briefly review some of these advances before focusing on the recently discovered and particularly promising spin-orbit torques which act on the collective spin of thin film magnetic conductors when they are placed on a substrate with strong spin-orbit interactions. Spin-orbit torques are normally interpreted in terms of the spin Hall effect, spin-current that flows perpendicular to charge current in any conductor.
Welcome and Opening Remarks
Scientific Organizer:
- Anton Burkov, University of Waterloo
- Jan Kycia, University of Waterloo