Effect of spin-orbit interactions on the 0.7 anomaly in quantum point contacts

TL;DR

This paper investigates how spin-orbit interactions influence the conductance and 0.7 anomaly in quantum point contacts, revealing that magnetic field tuning can significantly alter electron behavior and conductance features.

Contribution

It provides a detailed analysis of the interplay between spin-orbit coupling, magnetic fields, and electron interactions in quantum point contacts, highlighting new effects on conductance anomalies.

Findings

Spin-orbit interactions modify the local density of states.

Magnetic field tuning affects the 0.7-anomaly shape.

Additional features appear in the first conductance step.

Abstract

We study how the conductance of a quantum point contact is affected by spin-orbit interactions, for systems at zero temperature both with and without electron-electron interactions. In the presence of spin-orbit coupling, tuning the strength and direction of an external magnetic field can change the dispersion relation and hence the local density of states in the point contact region. This modifies the effect of electron-electron interactions, implying striking changes in the shape of the 0.7-anomaly and introducing additional distinctive features in the first conductance step.