# Coupled qubits as a quantum heat switch

## TL;DR

This paper proposes a quantum heat switch using coupled superconducting qubits controlled by magnetic flux, demonstrating enhanced power transmission and tunable bandwidth, with potential applications in quantum thermal management.

## Contribution

It introduces a novel quantum heat switch design based on coupled qubits, analyzing its performance and control via magnetic flux, which was not previously explored in this context.

## Key findings

- Finite qubit coupling enhances transmitted power by an order of magnitude.
- Magnetic flux controls the energy levels and switching behavior.
- Bandwidth at maximum power is narrowed in the coupled system.

## Abstract

We present a quantum heat switch based on coupled superconducting qubits, connected to two $LC$ resonators that are terminated by resistors providing two heat baths. To describe the system we use a standard second order master equation with respect to coupling to the baths. We find that this system can act as an efficient heat switch controlled by the applied magnetic flux. The flux influences the energy level separations of the system, and under some conditions, the finite coupling of the qubits enhances the transmitted power between the two baths, by an order of magnitude under realistic conditions. At the same time, the bandwidth at maximum power of the switch formed of the coupled qubits is narrowed.