Magnon Hall conductivity and thermal transport in frustrated antiferromagnets

Abstract

The spin Hall conductivity, σxy(ω) is studied in the quantum frustrated two-dimensional bilayer anisotropic Heisenberg model in the triangular lattice in an external magnetic field employing linear spin waves. Our results show a spin Hall conductivity nonzero when the external field hz is different from zero. Moreover, we present the study of the thermal transport by spin excitations for the two-dimensional frustrated monolayer Heisenberg model in the triangular lattice. We also employ the linear spin wave theory to investigate the dependence on T of the thermal Drude weight in this case. We present our results for the dependence on T of the thermal Drude weight in the gapless regime. Our results show an ideal thermal conductivity for T > 0 as expected for gapless spin systems, and an insulator thermal transport at T=0.