Temperature Dependence of Spin-Split Peaks in Transverse Electron Focusing

TL;DR

This study investigates how temperature affects spin-split peaks in transverse electron focusing in GaAs, revealing that spin polarization effects are prominent at low temperatures but diminish as temperature increases.

Contribution

The paper provides experimental evidence of temperature-dependent spin splitting in electron focusing, highlighting the role of exchange-driven spin polarization in GaAs.

Findings

Spin-split peaks are well-defined at low temperatures.

Peak splitting smears out at high temperatures.

Exchange-driven spin polarization dominates at low temperatures.

Abstract

We present experimental results of transverse electron-focusing measurements performed using n-type GaAs. In the presence of a small transverse magnetic field (B), electrons are focused from the injector to detector leading to focusing peaks periodic in B. We show that the odd-focusing peaks exhibit a split, where each sub-peak represents a population of a particular spin branch emanating from the injector. The temperature dependence reveals that the peak splitting is well defined at low temperature whereas it smears out at high temperature indicating the exchange-driven spin polarisation in the injector is dominant at low temperatures.