Stochastic Energetics of Quantum Transport

TL;DR

This paper investigates the stochastic energetics of quantum ratchets, showing quantum advantages in efficiency at low temperatures and analyzing how classical and quantum efficiencies compare under different conditions.

Contribution

It provides a detailed analysis of quantum efficiency in ratchet devices, highlighting differences from classical systems and the impact of temperature and load.

Findings

Quantum current and efficiency are higher than classical ones at low temperature.

Quantum efficiency without load surpasses classical efficiency.

Maximum efficiency is independent of bath and potential in both classical and quantum systems.

Abstract

We examine the stochastic energetics of directed quantum transport due to rectification of non-equilibrium thermal fluctuations. We calculate the quantum efficiency of a ratchet device both in presence and absence of an external load to characterize two quantifiers of efficiency. It has been shown that the quantum current as well as efficiency in absence of load (Stokes efficiency) is higher as compared to classical current and efficiency, respectively, at low temperature. The conventional efficiency of the device in presence of load on the other hand is higher for a classical system in contrast to its classical counterpart. The maximum conventional efficiency being independent of the nature of the bath and the potential remains the same for classical and quantum systems.