Realization of all-optical underdamped stochastic Stirling engine

TL;DR

This paper experimentally demonstrates a nano-scale stochastic Stirling engine operating in the underdamped regime, revealing insights into its performance, fluctuations, and non-Gaussian behavior under different cycle conditions.

Contribution

The study presents the first experimental realization of an all-optical underdamped stochastic Stirling engine and analyzes its thermodynamic performance and fluctuation characteristics.

Findings

Output work and efficiency approach theoretical limits in quasi-static conditions.

Work fluctuation distribution is Gaussian in quasi-static regime and becomes non-Gaussian at shorter cycle times.

Non-Gaussianity is linked to strong correlations in the non-equilibrium regime.

Abstract

We experimentally demonstrate a nano-scale stochastic Stirling heat engine operating in the underdamped regime. The setup involves an optically levitated silica particle that is subjected to a power-varying optical trap and periodically coupled to a cold/hot reservoir via switching on/off active feedback cooling. We conduct a systematic investigation of the engine's performance and find that both the output work and efficiency approach their theoretical limits under quasi-static conditions. Furthermore, we examine the dependence of the output work fluctuation on the cycle time and temperature difference between the hot and cold reservoirs. We observe that the distribution has a Gaussian profile in the quasi-static regime, whereas it becomes asymmetric and non-Gaussian as the cycle duration time decreases. This non-Gaussianity is qualitatively attributed to the strong correlation of the particle's position within a cycle in the non-equilibrium regime. Our experiments provide valuable insights into stochastic thermodynamics in the underdamped regime and open up new possibilities for the design of future nano-machines.