0.7 Structure and Zero Bias Anomaly in Ballistic Hole Quantum Wires

TL;DR

This study investigates how in-plane magnetic fields influence the 0.7 conductance anomaly and zero-bias peak in ballistic hole quantum wires, revealing anisotropic spin effects and the fundamental role of spin in these phenomena.

Contribution

It provides new insights into the anisotropic magnetic field effects on conductance anomalies in hole quantum wires, emphasizing the importance of spin and effective g-factor anisotropy.

Findings

Magnetic fields shift the 0.7 conductance plateau to 0.5(2e^2/h)

Zero bias anomaly is quenched by magnetic fields

Effects depend strongly on magnetic field orientation due to g-factor anisotropy

Abstract

We study the anomalous conductance plateau around $G = 0.7(2e^{2}/h)$ and the zero-bias anomaly in ballistic hole quantum wires with respect to in-plane magnetic fields applied parallel $B_{\parallel}$ and perpendicular $B_{\perp}$ to the quantum wire. As seen in electron quantum wires, the magnetic fields shift the 0.7 structure down to $G = 0.5(2e^{2}/h)$ and simultaneously quench the zero bias anomaly. However, these effects are strongly dependent on the orientation of the magnetic field, owing to the highly anisotropic effective Land\'{e} \emph{g}-factor $g^{*}$ in hole quantum wires. Our results highlight the fundamental role that spin plays in both the 0.7 structure and zero bias anomaly.