Effects of short-range interactions on transport through quantum point contacts: A numerical approach

TL;DR

This paper uses a numerical non-equilibrium Green function method at Hartree-Fock level to investigate how short-range electron interactions influence quantum point contact conductance, reproducing the 0.7 anomaly and related features.

Contribution

It introduces a numerical approach to model electron interactions in quantum point contacts, capturing the 0.7 anomaly and connecting electronic and atomic transport phenomena.

Findings

Reproduces the 0.7 conductance anomaly at low temperatures.

Shows the anomaly is consistent with a spin-splitting interpretation.

Suggests the anomaly could be observed in ultracold atom experiments.

Abstract

We study electronic transport through a quantum point contact, where the interaction between the electrons is approximated by a contact potential. Our numerical approach is based on the non-equilibrium Green function technique which is evaluated at Hartree-Fock level. We show that this approach allows us to reproduce relevant features of the so-called "0.7 anomaly" observed in the conductance at low temperatures, including the characteristic features in recent shot noise measurements. This is consistent with a spin-splitting interpretation of the process, and indicates that the "0.7 anomaly" should also be observable in transport experiments with ultracold fermionic atoms.