The theory of the "0.7 anomaly" in quantum point contacts

TL;DR

This paper explains the 0.7 anomaly in quantum point contacts through a quasi-localized state, supported by numerical calculations that match experimental conductance and noise data.

Contribution

It introduces a model based on a quasi-localized state formation to explain the 0.7 anomaly, validated by spin-density functional theory calculations.

Findings

Numerical confirmation of a quasi-localized state in quantum point contacts.

Quantitative conductance and noise calculations match experimental data.

The model provides a comprehensive explanation of the 0.7 anomaly.

Abstract

The phenomenology of the "0.7 anomaly" in quantum point contacts is fully explained in terms of a quasi-localized state, which forms as the point contact opens up. Detailed numerical calculations within spin-density functional theory indeed con rm the emergence of such a state. Quantitative calculations of the conductance and the noise are obtained using a model based on these observations, and are in excellent agreement with existing experimental observations.