Quantum spin liquid at finite temperature: Proximate dynamics and persistent typicality
journal contributionposted on 2019-07-15, 09:26 authored by Ioannis RousochatzakisIoannis Rousochatzakis, S. Kourtis, J. Knolle, R. Moessner, Natalia B. Perkins
Quantum spin liquids are long-range entangled states of matter with emergent gauge fields and fractionalized excitations. While candidate materials, such as the Kitaev honeycomb ruthenate α-RuCl3, show magnetic order at low temperatures T , here we demonstrate numerically a dynamical crossover from magnonlike behavior at low T and frequencies ω to long-lived fractionalized fermionic quasiparticles at higher T and ω. This crossover is akin to the presence of spinon continua in quasi-1D spin chains. It is further shown to go hand in hand with persistent typicality down to very low T . This aspect, which has also been observed in the spin-1/2 kagome Heisenberg antiferromagnet, is a signature of proximate spin liquidity and emergent gauge degrees of freedom more generally, and can be the basis for the numerical study of many finite-T properties of putative spin liquids.
Deutsche Forschungsgemeinschaft via grant SFB 1143. Boston University Center for Non-Equilibrium Systems and Computation. U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award #DE- SC0018056.