Quantum Heat Engines with Carnot Efficiency at Maximum Power

TL;DR

This paper demonstrates quantum heat engines that can achieve Carnot efficiency at maximum power in finite-size, one-shot regimes by leveraging quantum entanglement and coherent heat transfer, challenging traditional power-efficiency trade-offs.

Contribution

It introduces a novel quantum heat engine model that attains Carnot efficiency at maximum power in finite systems using semi-local thermal operations and entanglement.

Findings

Achieves Carnot efficiency at maximum power in finite quantum systems.

Utilizes quantum entanglement for optimal heat transfer.

Proposes a feasible implementation with quantum optical systems.

Abstract

Heat engines constitute the major building blocks of modern technologies. However, conventional heat engines with higher power yield lesser efficiency and vice versa and respect various power-efficiency trade-off relations. This is also assumed to be true for the engines operating in the quantum regime. Here we show that these relations are not fundamental. We introduce quantum heat engines that deliver maximum power with Carnot efficiency in the one-shot finite-size regime. These engines are composed of working systems with a finite number of quantum particles and are restricted to one-shot measurements. The engines operate in a one-step cycle by letting the working system simultaneously interact with hot and cold baths via semi-local thermal operations. By allowing quantum entanglement between its constituents and, thereby, a coherent transfer of heat from hot to cold baths, the engine implements the fastest possible reversible state transformation in each cycle, resulting in maximum power and Carnot efficiency. Finally, we propose a physically realizable engine using quantum optical systems.