Fluctuations of stochastic currents in an autonomous linear engine

Wenqi Lin¹, Yi-Hung Liao^1*, Yonggun Jun¹

¹Department of Physics, National Central University, Zhongli, Taoyuan, Taiwan

* Presenter:Yi-Hung Liao, email:yihungliao@ncu.edu.tw

Controlling the current of thermodynamic quantity such as heat and work is critical for a microscopic heat engine to convert harvested energy to mechanical work. The theory of the thermodynamic uncertainty relation (TUR) predicts a trade-off between entropy production and fluctuations of thermodynamic currents. We here provide experimental verification of TUR and the attainability of Carnot efficiency in an autonomous linear engine. This engine is a Brownian gyrator of a colloidal particle confined in two-dimensional harmonic potential with separate temperatures to orthogonal axes virtually generated by an optical feedback trap. We validate the theoretical attainability of Carnot efficiency and TUR in our autonomous linear engine. Our experimental demonstration promises a convenient examination of maximum power output at beyond-Carnot-limit efficiency for a heat engine in active baths.

Keywords: Stochastic thermodynamics, Thermodynamic uncertainty relation, Brownian gyrator, Optical feedback trap, Autonomous linear engine