Optimal performance of a quantum Otto refrigerator

TL;DR

This paper analyzes the efficiency of a quantum Otto refrigerator with a harmonic oscillator, deriving optimal performance conditions and limits for adiabatic and nonadiabatic protocols in quantum and classical regimes.

Contribution

It provides analytical expressions for optimal performance and minimal driving times, advancing understanding of quantum refrigerator efficiency under various driving conditions.

Findings

Optimal performance expressions for quantum and classical regimes

Breakdown conditions for nonadiabatic driving protocols

Minimal driving time estimates for effective cooling

Abstract

We consider a quantum Otto refrigerator cycle of a time-dependent harmonic oscillator. We investigate the coefficient of performance at maximum figure of merit for adiabatic and nonadiabatic frequency modulations. We obtain analytical expressions for the optimal performance both in the high-temperature (classical) regime and in the low-temperature (quantum) limit. We moreover analyze the breakdown of the cooling cycle for strongly nonadiabatic driving protocols and derive analytical estimates for the minimal driving time allowed for cooling.