Voltage-amplified heat rectification in SIS junctions

TL;DR

This paper proposes a simple method to achieve high heat rectification in SIS junctions by applying a fast oscillating voltage, enabling control of heat flow with potential for sharp rectification performance.

Contribution

It introduces a novel approach using oscillating voltage in SIS junctions to significantly enhance heat rectification, highlighting quantum coherence effects.

Findings

Rectification coefficient up to approximately 500

Sharp increase in rectification beyond adiabatic regime

Quantum coherence influences heat rectification

Abstract

The control of thermal fluxes -- magnitude and direction, in mesoscale and nanoscale electronic circuits can be achieved by means of heat rectification using thermal diodes in two-terminal systems. The rectification coefficient $\mathcal{R}$, given by the ratio of forward and backward heat fluxes, varies with the design of the diode and the working conditions under which the system operates. A value of $\mathcal{R}\ll 1$ or $\mathcal{R}\gg 1$ is a signature of high heat rectification performance but current solutions allowing such ranges, necessitate rather complex designs. Here, we propose a simple solution: the use of a superconductor-insulator-superconductor (SIS) junction under an applied fast oscillating (THz range) voltage as the control of the heat flow direction and magnitude can be done by tuning the initial value of the superconducting phase. Our theoretical model based on the Green functions formalism and coherent transport theory, shows a possible sharp rise of the heat rectification coefficient with values up to $\mathcal{R} \approx 500$ beyond the adiabatic regime. The influence of quantum coherent effects on heat rectification in the SIS junction is highlighted.