“Challenges and Prospects of Kitaev Magnet α-RuCl3”

Dr. Kwang Yong Choi
Department of Physics, Chung-Ang University

Feb. 9 (Tue.), 01:30 PM
Online seminar
https://kaist.zoom.us/j/86593232866
회의 ID: 865 9323 2866
암호: 404052

Abstract:
The celebrated Kitaev honeycomb model provides a novel platform to achieve a Z2 quantum spin liquid and Majorana quasiparticles. More significantly, applying a magnetic field engenders a non-Abelian chiral spin liquid, featuring both gapped charge-neutral fermions and Ising anyons—Majorana zero modes bound to Z2 vortices. The bulk-boundary correspondence predicts the existence of a gapless chiral Majorana fermion mode at the edge, which is responsible for a quantized thermal Hall effect. This has stimulated a great deal of theoretical and experimental efforts towards materializations of the Kitaev spin liquid. Recent efforts have focused on the two-dimensional layered ruthenate α-RuCl3 as the forefront of searches for Kitaev candidate materials.
In this talk, I will first review the debated issues of α-RuCl3, namely, the nature of the intermediate field-induced phase of μ0H≈7-9 T, in which a half-integer quantized thermal Hall effect is observed. Second, I will discuss an on-going project on elucidating the electronic and magnetic properties of mechanically exfoliated α-RuCl3 as well as of α-RuCl3/graphene. Finally, I will introduce theoretical schemes to probe electronically the charge-neutral topological states in insulating quantum magnets.