On the Zero-Bias Anomaly in Quantum Wires

TL;DR

This paper investigates the Zero-Bias Anomaly in quantum wires made from undoped GaAs/AlGaAs heterostructures, comparing experimental observations with theoretical models and highlighting discrepancies in spin-related behaviors.

Contribution

It critically evaluates Kondo and spin polarization models against experimental data, revealing their limitations in explaining the Zero-Bias Anomaly.

Findings

Zero-Bias Anomaly shows linear electron-density dependence.

Suppression of Zeeman effect at pinch-off.

Discrepancies challenge existing theoretical models.

Abstract

Undoped GaAs/AlGaAs heterostructures have been used to fabricate quantum wires in which the average impurity separation is greater than the device size. We compare the behavior of the Zero-Bias Anomaly against predictions from Kondo and spin polarization models. Both theories display shortcomings, the most dramatic of which are the linear electron-density dependence of the Zero-Bias Anomaly spin-splitting at fixed magnetic field B and the suppression of the Zeeman effect at pinch-off.