Exponential speedup of incoherent tunneling via dissipation

TL;DR

This paper demonstrates that dissipation coupled to momentum can exponentially enhance the escape rate of a particle in a metastable potential, with effects depending on the barrier slope and dissipation type.

Contribution

It introduces a semiclassical approach to show how momentum dissipation can exponentially increase tunneling escape rates, revealing non-monotonic effects with combined dissipation types.

Findings

Momentum dissipation exponentially enhances escape rates.

Dissipation effects depend on barrier slope and coupling strength.

Combined position and momentum dissipation can lead to non-monotonic behaviors.

Abstract

We study the escape rate of a particle in a metastable potential in presence of a dissipative bath coupled to the momentum of the particle. Using the semiclassical bounce technique, we find that this rate is exponentially enhanced. In particular, the influence of momentum dissipation depends on the slope of the barrier that the particle is tunneling through. We investigate also the influence of dissipative baths coupled to the position, and to the momentum of the particle, respectively. In this case the rate exhibits a non-monotonic behavior as a function of the dissipative coupling strengths. Remarkably, even in presence of position dissipation, momentum dissipation can enhance exponentially the escape rate in a large range of the parameter space. The influence of the momentum dissipation is also witnessed by the substantial increase of the average energy loss during inelastic (environment-assisted) tunneling.