Intrinsic Bistability In Quantum Point Contacts with in-plane Side Gates

TL;DR

This paper investigates how intrinsic bistability and hysteresis in quantum point contacts are influenced by spin-orbit coupling, electron interactions, and device geometry, revealing multistable spin textures in conductance anomalies.

Contribution

It demonstrates the emergence of hysteresis linked to multistable spin textures in QPCs with in-plane gates, highlighting the role of electron interactions and device length.

Findings

Hysteresis appears only in sufficiently long QPCs.

Electron-electron interactions enhance hysteresis.

Hysteresis occurs in conductance regions below 2e2/h.

Abstract

We study the onset of intrinsic bistability and accompanying hysteresis in a single quantum point contact (QPC) with in-plane side gates in the presence of lateral spin-orbit coupling. The hysteresis in the conductance versus common gate voltage applied to the two side gates exists only if the narrow portion of the QPC is long enough. The hysteresis is absent if the effects of electron-electron interaction are neglected but increases with the strength of the electron-electron interaction. The hysteresis appears in the region of conductance anomalies, i.e., less than 2e2/h, and is due to multistable spin textures in these regions.