Enhancement mechanism of the electron g-factor in quantum point contacts

TL;DR

This paper explains the experimentally observed enhancement of the electron g-factor in quantum point contacts by proposing a theory that accounts for electron-electron interactions and the non-equilibrium conditions during spectroscopy.

Contribution

It introduces a novel theoretical explanation for the g-factor enhancement, emphasizing the role of electron-electron interactions and finite bias conditions.

Findings

The g-factor enhancement depends on non-equilibrium effects.

Electron-electron interactions are crucial for the observed phenomenon.

The theory aligns with experimental observations.

Abstract

The electron g-factor measured in a quantum point contact by source-drain bias spectroscopy is significantly larger than its value in a two-dimensional electron gas. This enhancement, established experimentally in numerous studies, is an outstanding puzzle. In the present work we explain the mechanism of this enhancement in a theory accounting for the electron-electron interactions. We show that the effect relies crucially on the non-equilibrium nature of the spectroscopy at finite bias.