Experimental Verification of Demon-Involved Fluctuation Theorems

TL;DR

This paper experimentally verifies new fluctuation theorems involving Maxwell's demon using ultracold calcium ions, demonstrating the intrinsic nonequilibrium nature and providing insights into information thermodynamics at the microscale.

Contribution

First experimental verification of fluctuation theorems involving Maxwell's demon in an ultracold ion system, confirming theoretical predictions and revealing tighter bounds on work and efficacy.

Findings

Confirmed the nonequilibrium nature due to demon involvement

Provided quantitative evidence of dissipative information

Observed bounds tighter than Sagawa-Ueda theorem predictions

Abstract

The limit of energy saving in the control of small systems has recently attracted much interest due to the concept refinement of the Maxwell demon. Inspired by a newly proposed set of fluctuation theorems, we report the first experimental verification of these equalities and inequalities in a ultracold 40Ca ion system, confirming the intrinsic nonequilibrium in the system due to involvement of the demon. Based on elaborately designed demon-involved control protocols, such as the Szilard engine protocol, we provide experimentally quantitative evidence of the dissipative information, and observe tighter bounds of both the extracted work and the demon's efficacy than the limits predicted by the Sagawa-Ueda theorem. Our results substantiate a close connection between the physical nature of information and nonequilibrium processes at the microscale, which help further understanding the thermodynamic characteristics of information and the optimal design of nanoscale and smaller systems.