Exploring Kitaev Magnetism Beyond the Honeycomb Lattice
Mar 24, 2023
2:30PM to 3:30PM
Date(s) - 24/03/2023
2:30 pm - 3:30 pm
Prof. Pat Clancy
Dept. of Physics and Astronomy, McMaster University
The properties of heavy 5d transition metal oxides, such as iridates and osmates, are often remarkably different from those of their lighter 3d counterparts. In particular, the presence of strong spin-orbit coupling (SOC) can give rise to a variety of exotic quantum states, including spin-orbital Mott insulators, topological insulators, Weyl semimetals, and quantum spin liquids. In materials based on edge-sharing octahedral crystal structures, large SOC can also lead to unconventional magnetism, and a form of highly anisotropic, bond-directional Ising interaction known as the Kitaev interaction. The first, and best known, experimental realizations of Kitaev magnetism are honeycomb lattice materials: the 5d iridates A2IrO3 (A = Na, Li) and the 4d halide ?-RuCl3. These compounds have attracted considerable attention due to predictions of a Kitaev quantum spin liquid with exotic anyonic excitations. However, there has recently been growing interest in the search for Kitaev magnetism in other families of materials with different lattice geometries. In this talk, I will describe several candidates for Kitaev magnetism beyond the honeycomb lattice. This will include (1) potential face-centered-cubic (fcc) Kitaev systems, such as the double perovskite iridates (A2BIrO6) and iridium halides (A2IrX6), and (2) potential realizations of Kitaev chains in quasi-1D iridates.
Pat Clancy is an Assistant Professor in the Dept. of Physics and Astronomy at McMaster University and a member of the Brockhouse Institute for Materials Research. His research focuses on the study of novel quantum materials, such as low-dimensional and geometrically frustrated magnets, spin-orbit-driven materials, and high temperature superconductors. In particular, Pat’s research group specializes in sample synthesis and crystal growth of new materials, and the investigation of their structural and magnetic properties using x-ray and neutron scattering techniques. Pat received his B.Sc. in Physics from St. Francis Xavier University, and his M.Sc. and Ph.D. in Physics from McMaster. He completed a postdoctoral fellowship at the University of Toronto, and has previously held positions as an Assistant Professor at Trent University and as a neutron instrument scientist at the McMaster Nuclear Reactor. He has held Banting, Heater, and McCall MacBain postdoctoral fellowships, and was awarded the John Charles Polanyi Prize in Physics for Early Career Research.