Hysteresis and spin phase transitions in quantum wires in the integer quantum Hall regime

TL;DR

This paper investigates hysteresis in electronic transport within quantum wires under the integer quantum Hall regime, revealing spin phase transitions influenced by many-body interactions and confinement potential slopes.

Contribution

It demonstrates the occurrence of hysteresis due to spin phase transitions in quantum wires and explains the conditions under which this behavior appears or disappears.

Findings

Hysteresis occurs only for intermediate confinement slopes.

Hysteresis is linked to phase spin transitions between polarized and non-polarized states.

The effect is absent for steep and smooth confining potentials.

Abstract

We demonstrate that a split-gate quantum wire in the integer quantum Hall regime can exhibit electronic transport hysteresis for up- and down-sweeps of a magnetic field. This behavior is shown to be due to phase spin transitions between two different ground states with and without spatial spin polarization in the vicinity of the wire boundary. The observed effect has a many-body origin arising from an interplay between a confining potential, Coulomb interactions and the exchange interaction. We also demonstrate and explain why the hysteretic behavior is absent for steep and smooth confining potentials and is present only for a limited range of intermediate confinement slopes.