Quantum diffusion in biased washboard potentials: strong friction limit

TL;DR

This paper investigates how quantum effects like tunneling and fluctuations influence the diffusion of a quantum particle in a biased periodic potential under strong friction, revealing enhanced transport efficiency at certain temperatures.

Contribution

It provides a detailed analysis of quantum diffusion in tilted washboard potentials, highlighting the significant role of quantum effects in transport properties under strong friction.

Findings

Quantum effects substantially enhance diffusion at intermediate temperatures.

Quantum tunneling and fluctuations increase the effective diffusion coefficient.

The Peclet number indicates improved transport efficiency due to quantum phenomena.

Abstract

Diffusive transport properties of a quantum Brownian particle moving in a tilted spatially periodic potential and strongly interacting with a thermostat are explored. Apart from the average stationary velocity, we foremost investigate the diffusive behavior by evaluating the effective diffusion coefficient together with the corresponding Peclet number. Corrections due to quantum effects, such as quantum tunneling and quantum fluctuations, are shown to substantially enhance the effectiveness of diffusive transport if only the thermostat temperature resides within an appropriate interval of intermediate values.