A many-body Szilard engine with giant number fluctuations

TL;DR

This paper experimentally demonstrates a macroscopic many-particle Szilard engine using active particles, revealing that giant number fluctuations lead to increased extractable work with more particles, contrasting thermal particle behavior.

Contribution

It introduces a novel experimental realization of a many-body Szilard engine with active particles and explores how giant number fluctuations enhance work extraction.

Findings

Extractable work increases with the number of particles due to giant number fluctuations.

Gradually changing the weight during the cycle increases work output.

Active particles enable a macroscopic realization of the Szilard engine.

Abstract

Szil\'ard's information engine is a canonical example in the field of thermodynamics of information. We realize experimentally a macroscopic many-particle Szil\'ard engine that consists of active particles and use it to lift a mass against gravity. We show that the extractable work per cycle increases when the raised weight is changed more gradually during the process. Interestingly, we find that the ideal extractable work grows with the number of particles due to giant number fluctuations. This is in contrast to the calculated behavior of a similar engine operating on thermal particles.