Exchange Interaction Effects on the Conductance of Quantum Wires

TL;DR

This paper investigates how exchange interactions influence the conductance quantization in ballistic quantum wires, explaining nonuniversal conductance steps through many-particle fermion exchange effects, aligning with experimental observations.

Contribution

It introduces a many-particle wave packet formalism to explain nonuniversal conductance quantization as a fermion exchange interaction effect.

Findings

Exchange interactions cause reductions in conductance steps.

The model reproduces experimental conductance reductions in GaAs/AlGaAs quantum wires.

The approach explains the nonuniversal conductance quantization observed experimentally.

Abstract

The effect of exchange interaction on the two-terminal conductance of fully ballistic samples is studied using a many-particle wave packet formalism. The approach shows that the puzzling nonuniversal conductance quantization can be explained as a fermion exchange interaction effect. The Landauer conductance step Go is obtained when two-fermion interaction is considered. Reductions of Go are due to a many-particle exchange interaction effect. For ballistic GaAs/AlGaAs quantum wires longer than 1 um, a conductance step reduction is obtained in agreement with experimental results.