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

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.