Zeno-Assisted Quantum Heat Engines

TL;DR

This paper introduces a quantum lubrication protocol using quantum Zeno dynamics to improve the efficiency and power of finite-time quantum heat engines by mitigating quantum friction effects.

Contribution

The authors propose a novel Zeno-assisted quantum lubrication method that effectively shortcuts adiabaticity in quantum heat engines, enhancing performance.

Findings

Reproduces transitionless dynamics in ideal Zeno limit

Recovers Otto efficiency at finite stroke durations

Analyzes thermodynamic costs affecting practical gains

Abstract

Finite-time quantum heat engines (QHEs) typically extract less work than their quasistatic counterparts because fast driving generates coherences and non-adiabatic transitions during the work strokes, a phenomenon commonly referred to as quantum friction. Quantum lubrication denotes a broad class of strategies that use auxiliary systems or controls to mitigate this loss. In this work, we introduce a lubrication protocol based on the quantum Zeno dynamics (QZD). By coupling the working medium to an auxiliary lubricant system and frequently monitoring the lubricant, we confine the joint evolution to a Zeno subspace and obtain an effective shortcut to adiabaticity during the work strokes of a QHE running an Otto cycle. In the ideal Zeno limit, the protocol reproduces the transitionless dynamics required to preserve populations in the instantaneous energy basis and recover the Otto efficiency at finite stroke duration. We also analyze several implementation-dependent thermodynamic costs, including switching, driving, monitoring, and imperfect thermalization, in order to assess how these costs constrain the practical gains in efficiency and power. Our results identify QZD as a conceptually distinct route to quantum lubrication and highlight quantum heat engines as a useful setting in which to study the interplay between strong coupling, measurement, and quantum thermodynamic control.