Microcanonical Szil\'ard engines beyond the quasistatic regime

TL;DR

This paper explores finite-time microcanonical Szilard engines that extract energy from a thermal bath without quasistatic assumptions, using feedback protocols based on linear response theory, while maintaining fundamental physical principles.

Contribution

It extends the concept of Szilard engines beyond quasistatic regimes by proposing a feedback protocol for finite-time operation that respects Liouville's theorem and ergodicity.

Findings

Energy extraction is possible in finite time using the proposed feedback protocol.

The mechanism does not violate fundamental physical principles like Liouville's theorem.

Examples include an exactly solvable model demonstrating the concept.

Abstract

We discuss the possibility of extracting energy from a single thermal bath using microcanonical Szil\'ard engines operating in finite time. This extends previous works on the topic which are restricted to the quasistatic regime. The feedback protocol is implemented based on linear response predictions of the excess work. It is claimed that the underlying mechanism leading to energy extraction does not violate Liouville's theorem and preserves ergodicity throughout the cycle. We illustrate our results with several examples including an exactly solvable model.