Stochastically driven single level quantum dot: a nano-scale finite-time thermodynamic machine and its various operational modes

TL;DR

This paper models a quantum dot as a nanoscale thermodynamic machine driven by stochastic forces, capable of functioning as a battery, engine, or refrigerator, with analysis of its efficiency and universal behaviors.

Contribution

It introduces a stochastic-driven quantum dot model functioning in multiple thermodynamic modes and analyzes its efficiency and universal features at maximum power.

Findings

Operates as a rechargeable battery, engine, or refrigerator depending on conditions.

Can generate work against bias or extract heat from cold reservoir.

Identifies universal features in efficiency at maximum power.

Abstract

We describe a single-level quantum dot in contact with two leads as a nanoscale finite-time thermodynamic machine. The dot is driven by an external stochastic force that switches its energy between two values. In the isothermal regime, it can operate as a rechargeable battery by generating an electric current against the applied bias in response to the stochastic driving, and re-delivering work in the reverse cycle. This behavior is reminiscent of the Parrondo paradox. If there is a thermal gradient the device can function as a work-generating thermal engine, or as a refrigerator that extracts heat from the cold reservoir via the work input of the stochastic driving. The efficiency of the machine at maximum power output is investigated for each mode of operation, and universal features are identified.