A quantum heat engine with coupled superconducting resonators

TL;DR

This paper introduces a quantum heat engine using coupled superconducting resonators, demonstrating quantum-enhanced power output and analyzing quantum versus classical behaviors through detailed statistical and thermodynamic calculations.

Contribution

It presents a novel quantum heat engine design with superconducting resonators and explores quantum effects on power output and thermodynamic properties.

Findings

Quantum enhancement in power output at low temperatures

Emergence of a limit cycle indicating finite power

Differences between quantum and classical descriptions

Abstract

We propose a quantum heat engine composed of two superconducting transmission line resonators interacting with each other via an optomechanical-like coupling. One resonator is periodically excited by a thermal pump. The incoherently driven resonator induces coherent oscillations in the other one due to the coupling. A limit cycle, indicating finite power output, emerges in the thermodynamical phase space. The system implements an all-electrical analog of a photonic piston. Instead of mechanical motion, the power output is obtained as a coherent electrical charging in our case. We explore the differences between the quantum and classical descriptions of our system by solving the quantum master equation and classical Langevin equations. Specifically, we calculate the mean number of excitations, second-order coherence, as well as the entropy, temperature, power and mean energy to reveal the signatures of quantum behavior in the statistical and thermodynamic properties of the system. We find evidence of a quantum enhancement in the power output of the engine at low temperatures.