Non-dissipative Thermal Transport and Magnetothermal Effect for the Spin-1/2 Heisenberg Chain

TL;DR

This paper investigates anomalous magnetothermal effects in the spin-1/2 Heisenberg chain, revealing exact calculations of current correlations and the sign-changing behavior of the thermomagnetic coefficient due to strong correlations.

Contribution

It provides exact calculations of energy and spin current correlations and analyzes the low-temperature behavior of the thermomagnetic coefficient in the integrable model.

Findings

Energy and spin current correlations diverge at finite temperatures.

The thermomagnetic coefficient changes sign at specific interaction strengths and magnetic fields.

Exact lattice path integral formulation used for correlation calculations.

Abstract

Anomalous magnetothermal effects are discussed in the spin-1/2 Heisenberg chain. The energy current is related to one of the non-trivial conserved quantities underlying integrability and therefore both the diagonal and off diagonal dynamical correlations of spin and energy current diverge. The energy-energy and spin-energy current correlations at finite temperatures are exactly calculated by a lattice path integral formulation. The low-temperature behavior of the thermomagnetic (magnetic Seebeck) coefficient is also discussed. Due to effects of strong correlations, we observe the magnetic Seebeck coefficient changes sign at certain interaction strengths and magnetic fields.