Mesoscopic transport of fermions through an engineered optical lattice connecting two reservoirs

TL;DR

This paper investigates fermionic transport through an engineered optical lattice connecting two reservoirs, analyzing average current, fluctuations, and control mechanisms using advanced theoretical methods.

Contribution

It introduces a method to control atomic current via optical lattice engineering and discusses interaction effects, advancing quantum transport understanding in cold atom systems.

Findings

Average equilibration current calculated with nonequilibrium Green's functions

Significant shot-to-shot fluctuations observed in transport

Proposed control of atomic current through lattice potential engineering

Abstract

We study transport of fermions in a system composed of a short optical lattice connecting two finite atomic reservoirs at different filling levels. The average equilibration current through the optical lattice, for strong lattice-reservoir coupling and finite temperatures, is calculated within the Landauer formalism using a nonequilibrium Green's functions approach. We moreover determine quantum and thermal fluctuations in the transport and find significant shot-to-shot deviations from the average equilibration current. We show how to control the atomic current by engineering specific optical lattice potentials without requiring site-by-site manipulations and suggest the realization of a single level model. Based on this model we discuss the blocking effect on the atomic current resulting from weak interactions between the fermions.