Performance of superadiabatic quantum machines

TL;DR

This paper analyzes the efficiency and power of a quantum harmonic Otto engine using shortcut-to-adiabaticity techniques, deriving quantum speed limit bounds that outperform traditional thermodynamic limits.

Contribution

It introduces quantum speed limit-based bounds on efficiency and power for quantum heat engines, explicitly accounting for energetic costs of superadiabatic driving.

Findings

Quantum bounds are tighter than second law limits.

Efficiency and power depend on superadiabatic driving costs.

Derived bounds apply generally to driven quantum systems.

Abstract

We investigate the performance of a quantum thermal machine operating in finite time based on shortcut-to-adiabaticity techniques. We compute efficiency and power for a quantum harmonic Otto engine by taking the energetic cost of the superadiabatic driving explicitly into account. We further derive generic upper bounds on both quantities, valid for any heat engine cycle, using the notion of quantum speed limits for driven systems. We demonstrate that these quantum bounds are tighter than those stemming from the second law of thermodynamics.