Quantum Optical Two-Atom Thermal Diode

TL;DR

This paper introduces a quantum-optical model for a thermal diode using two interacting qubits, demonstrating non-reciprocal heat flow through anisotropic interactions and Raman processes, with potential implementations in various quantum platforms.

Contribution

It presents a novel quantum thermal diode model based on anisotropic qubit interactions and Raman transitions, enabling high-efficiency heat rectification.

Findings

Heat flow can be rectified with equal dissipation rates and resonant qubits.

Rectification is explained by four-wave mixing and Raman transitions.

The model is feasible in optomechanical, trapped ions, and circuit QED systems.

Abstract

We put forward a quantum-optical model for a thermal diode based on heat transfer between two thermal baths through a pair of interacting qubits. We find that if the qubits are coupled by a Raman field that induces an anisotropic interaction, heat flow can become non-reciprocal and undergoes rectification even if the baths have equal dissipation rates and/or the qubits are resonant. The heat flow rectification is explained by four-wave mixing and Raman transitions between dressed states of the interacting qubits and are governed by a global master equation. The anisotropic two-qubit interaction is the key for this present simple quantum thermal diode, whose resonant operation allows for high-efficiency rectification of large heat currents. Effects of spatial overlap of the baths are addressed. We also discuss the possible realizations of the model system in various platforms including optomechanical systems, systems of trapped ions, and circuit QED.