Complexity and Clarity for Kitaev Candidate Materials
Dr.
Steve
Winter
Assistant
Professor
Department
of
Physics
Wake
Forest
University
Winston-Salem,
North
Carolina
Wednesday,
December
14,
2022
2:30
p.m.
In-person:
C2-
361
(Reading
Room)
and
Online
via
MS
Teams (please
email
Victoria
Van
Cappellen
at vvancapp@uwaterloo.ca for
access)
Abstract: Quantum materials represent a broad class of systems whose experimental response relies directly on entanglement between their underlying degrees of freedom. Modeling of such materials presents a variety of challenges related to a disparate variety of complex behaviours that manifest at different energy scales, and a typical sensitivity of responses to model parameters. In this field, first-principles approaches often provide a vital bridge between experiments and theoretical models. In this talk, I will introduce our numerical strategies for systematically building low-energy models with local charge, spin, and orbital degrees of freedom of arbitrary complexity. I will discuss the insights that these methods have yielded for frustrated magnetic insulators collectively known as "Kitaev materials", which have prompted a recent explosion of interest in quantum magnets where spin-orbit coupling induces strongly anisotropic and competing magnetic interactions. I will specifically address our recent attempts to understand the magnetic models of few-layer RuCl3 and high-spin d7 Co(II) compounds, which have recently been identified as possible alternative platforms for realising the celebrated Kitaev model.