Heat rectification by two qubits coupled with Dzyaloshinskii-Moriya interaction

TL;DR

This paper explores heat rectification in a two-qubit system with Dzyaloshinskii-Moriya interaction, revealing how asymmetries and quantum coherence influence rectification efficiency and direction.

Contribution

It provides analytical expressions for heat currents and rectification, highlighting the role of asymmetry and quantum coherence in controlling heat flow in qubit systems.

Findings

Anisotropy of DM interaction alone does not cause rectification.

Off-resonant qubits introduce necessary asymmetry for rectification.

Quantum coherence asymmetry is key to rectifier performance.

Abstract

We investigate heat rectification in a two-qubit system coupled via the Dzyaloshinskii-Moriya (DM) interaction. We derive analytical expressions for heat currents and thermal rectification and provide possible physical mechanisms behind the observed results. We show that the anisotropy of DM interaction in itself is insufficient for heat rectification, and some other form of asymmetry is needed. We employ off-resonant qubits as the source of this asymmetry. We find the regime of parameters for higher rectification factors by examining the analytical expressions of rectification obtained from a global master equation solution. In addition, it is shown that the direction and quality of rectification can be controlled via various system parameters. Furthermore, we compare the influence of different orientations of the DM field anisotropy on the performance of heat rectification. Finally, we investigate the possible interplay between quantum correlations and the performance of the quantum thermal rectifier. We find that asymmetry in the coherences is a fundamental resource for the performance of the quantum thermal rectifier.