Quantum Measurement Cooling

TL;DR

This paper demonstrates how quantum measurements can be harnessed to create a cooling engine without feedback, relying on entanglement and measurement basis choices, with potential for robust experimental implementation.

Contribution

It introduces quantum measurement cooling (QMC) as a novel quantum thermodynamic process that does not require feedback control and highlights its robustness and implementation prospects.

Findings

QMC can operate without feedback control.

Entanglement in measurement projectors is essential.

High probability of QMC with random measurement basis.

Abstract

Invasiveness of quantum measurements is a genuinely quantum mechanical feature that is not necessarily detrimental: Here we show how quantum measurements can be used to fuel a cooling engine. We illustrate quantum measurement cooling (QMC) by means of a prototypical two-stroke two-qubit engine which interacts with a measurement apparatus and two heat reservoirs at different temperatures. We show that feedback control is not necessary for operation while entanglement must be present in the measurement projectors. We quantify the probability that QMC occurs when the measurement basis is chosen randomly, and find that it can be very large as compared to the probability of extracting energy (heat engine operation), while remaining always smaller than the most useless operation, namely dumping heat in both baths. These results show that QMC can be very robust to experimental noise. A possible low-temperature solid-state implementation that integrates circuit QED technology with circuit quantum thermodynamics technology is presented.