Particle current, noise, and counting statistics of quantum transport in the presence of a single-particle loss

TL;DR

This paper theoretically examines how a single-particle loss influences quantum transport, revealing that noise contains a measurable component proportional to the loss rate, with implications for ultracold atomic gas experiments.

Contribution

It derives a unified cumulant generating function for particle current in systems with single-particle loss, applicable to quantum point contact and quantum dot setups.

Findings

Current noise includes a component proportional to particle loss rate.

The generating function formalism is applicable to different mesoscopic systems.

Loss-induced noise may be experimentally measurable.

Abstract

How dissipation affects transport is an important theme in quantum science. Here we theoretically investigate an impact of a single-particle loss in mesoscopic transport, which has been an issue in experiments of ultracold atomic gases. By explicitly analyzing quantum point contact and quantum dot systems, we obtain a cumulant generating function on the particle current whose formal expression turns out to be common to two systems. In terms of this generating function, behaviors of average current, particle loss rate, and noises in presences of losses introduced in conduction channels are exemplified for free fermions. It is shown that the current noise contains the component proportional to the particle loss rate, which may be measurable in experiments.