Theoretical Nanophysics
print


Breadcrumb Navigation


Content

Via ZOOM: Field-driven spin liquid physics in Kitaev materials

Simon Trebst, University of Cologne

15.05.2020 at 10:15 

Abstract:
Kitaev materials — spin-orbit assisted Mott insulators, in which local, spin-orbit entangled j=1/2 moments form that are subject to strong bond-directional interactions — have attracted broad interest for their potential to realize spin liquids. Experimentally, a number of 4d and 5d systems have been widely studied including the honeycomb materials Na2IrO3, α-Li2IrO3, and RuCl3 as candidate spin liquid compounds — however, all of these materials magnetically order at sufficiently low temperatures. In this talk, I will discuss the physics of Kitaev materials that plays out when applying magnetic fields. Experiments on RuCl3 indicate the formation of a chiral spin liquid that gives rise to an observed quantized thermal Hall effect. Conceptually, this asks for a deeper understanding of the physics of the Kitaev model in tilted magnetic fields. I will report on our recent numerical studies that give strong evidence for a Higgs transition from the well known Z2 topological spin liquid to a gapless U(1) spin liquid with a spinon Fermi surface and put this into perspective of experimental studies. I will also discuss a recent experiment-theory collaboration probing the angular field-dependence of the quantized thermal Hall effect, which unambiguously demonstrate the formation of a Majorana Chern insulating state in RuCl3. 

 

If you are interested in joining, please email kathrin.higgen@lmu.de for ZOOM login details