A TBA description of thermal transport in the XXZ Heisenberg model

TL;DR

This paper demonstrates that the thermodynamic Bethe ansatz (TBA) approach for the 1D Heisenberg model accurately reproduces thermal transport properties previously obtained by the Quantum Transfer Matrix method and extends to non-equilibrium energy currents.

Contribution

It shows the TBA formulation can reproduce known thermal transport results and can be extended to study far-from-equilibrium energy currents in the XXZ Heisenberg model.

Findings

TBA reproduces thermal Drude weight and magnetothermal coefficient.

Extension of TBA to non-equilibrium energy transport.

Agreement with Quantum Transfer Matrix results.

Abstract

It is shown that the Bethe ansatz formulation of the easy-plane 1D Heisenberg model thermodynamics (TBA) by Takahashi and Suzuki and the subsequent analysis of the spin Drude weight, also reproduces the thermal Drude weight and magnetothermal coefficient obtained by the Quantum Transfer Matrix method (QTM). It can also be extended to study the far-out of equilibrium energy current generated at the interface between two semi-infinite chains held at different temperatures.