Dynamics and Transport of the Z2 Spin Liquid: Application to κ−(ET)2Cu2(CN)3

Abstract

We describe neutron scattering, NMR relaxation, and thermal transport properties of $Z_2$ spin liquids in two dimensions. Comparison to recent experiments on the spin $S=1/2$ triangular lattice antiferromagnet in $\kappa \mathrm{\text{−}}(\mathrm{ET}{)}_2{\mathrm{Cu}}_2(\mathrm{CN}{)}_3$ shows that this compound may realize a $Z_2$ spin liquid. We argue that the topological “vison” excitations dominate thermal transport, and that recent thermal conductivity experiments by M. Yamashita et al. have observed the vison gap.