Photonic heat rectification in a coupled qubits system

TL;DR

This paper proposes a quantum heat diode using coupled flux qubits, demonstrating how their coherent interaction enhances heat current rectification significantly, with potential for controlled heat flow manipulation.

Contribution

It introduces a theoretical model of a quantum heat diode with interacting flux qubits, showing how qubit interactions improve rectification and enable control over heat flow direction.

Findings

Rectification ratio up to ~3.5 achieved with realistic parameters.

Interaction enhances rectification by up to 230% over non-interacting case.

Rectification depends on entanglement and bath parameters.

Abstract

We theoretically investigate a quantum heat diode based on two interacting flux qubits coupled to two heat baths. Rectification of heat currents is achieved by asymmetrically coupling the qubits to the reservoirs modelled as dissipative $RLC$ resonators. We find that the coherent interaction between the qubits can be exploited to enhance the rectification factor, which otherwise would be constrained by the baths temperatures and couplings. Remarkably high values of rectification ratio up to $\mathcal R \sim 3.5$ can be obtained for realistic system parameters, with an enhancement up to $\sim 230\%$ compared to the non-interacting case. The system features the possibility of manipulating both the rectification amplitude and direction, allowing for an enhancement or suppression of the heat flow to a chosen bath. For the regime of parameters in which rectification is maximized, we find a significant increase of the rectification above a critical interaction value which corresponds to the onset of a non vanishing entanglement in the system. Finally, we discuss the dependence of the rectification factor on the bath temperatures and couplings.