Conductance Anomalies in Quantum Point Contacts and One Dimensional Wires

TL;DR

This paper reviews the 0.7 conductance anomaly in quantum point contacts and one-dimensional wires, discussing its experimental features and debating whether it signifies a fundamental physics question.

Contribution

It provides a critical analysis of the 0.7 anomaly, evaluating its significance and the extent to which it reflects a profound physical phenomenon.

Findings

The 0.7 anomaly appears over a conductance range of 0.25 to 0.95 Landauer quanta.

The paper critiques the interpretation of the anomaly as a fundamental physics problem.

It discusses experimental observations and theoretical perspectives on the anomaly.

Abstract

Over the last decade, interest in one-dimensional charge transport has progressed from the seminal discovery of Landauer quantization of conductance, as a function of carrier density, to finer-scale phenomena at the onset of quantization. This has come to be called the "0.7 anomaly", rather connoting a theoretical mystery of some profundity and universality, which remains open to date. Its somewhat imaginative appellation may tend to mislead, since the anomaly manifests itself over a range of conductance values: anywhere between 0.25 to 0.95 Landauer quanta. In this paper we offer a critique of the 0.7 anomaly and discuss the extent to which it represents a deep question of physics.