Quantum Point Contact with Local Two-body Loss

TL;DR

This paper studies a quantum transport system with local two-body loss, revealing how such loss affects current suppression and occupation dependence, relevant for ultracold atomic gas experiments.

Contribution

It introduces mesoscopic current formulas incorporating two-body loss effects using the Keldysh formalism, extending understanding beyond one-body loss scenarios.

Findings

Current suppression is weaker with two-body loss than with one-body loss.

Channel transmittance depends on nonequilibrium occupation at the lossy site.

Formulas are applicable in the weak dissipation regime.

Abstract

Motivated by recent advances in ultracold atomic gas experiments, we investigate a two-terminal mesoscopic system in which two-body loss occurs locally at the center of a one-dimensional chain. By means of the self-consistent Born approximation in the Keldysh formalism, we uncover mesoscopic current formulas that are experimentally relevant and applicable to the weak dissipation regime. Although these formulas are analogous to those for systems with one-body loss, it turns out that the channel transmittance and loss probability depend on the nonequilibrium occupation at the lossy site. We demonstrate that this occupation dependence leads to a weaker suppression of currents in the presence of two-body loss compared to one-body loss.