Electrical Control of Dynamic Spin Splitting Induced by Exchange Interaction as Revealed by Time Resolved Kerr Rotation in a Degenerate Spin-Polarized Electron Gas

TL;DR

This paper demonstrates electrical control of dynamic spin splitting in a spin-polarized electron gas via exchange interaction, using time-resolved Kerr rotation to reveal tunable spin splitting and phase reversal, with potential applications in spintronic devices.

Contribution

It introduces a method to electrically manipulate exchange-induced spin splitting in a degenerate electron gas, distinct from Rashba or Dresselhaus effects.

Findings

Spin splitting increases from 0.256meV to 0.559meV with bias.

Sign switch and phase reversal of Kerr signals observed with bias changes.

Electrical control enables potential spintronic device applications.

Abstract

The manipulation of spin degree of freedom have been demonstrated in spin polarized electron plasma in a heterostructure by using exchange-interaction induced dynamic spin splitting rather than the Rashba and Dresselhaus types, as revealed by time resolved Kerr rotation. The measured spin splitting increases from 0.256meV to 0.559meV as the bias varies from -0.3V to -0.6V. Both the sign switch of Kerr signal and the phase reversal of Larmor precessions have been observed with biases, which all fit into the framework of exchange-interaction-induced spin splitting. The electrical control of it may provide a new effective scheme for manipulating spin-selected transport in spin FET-like devices.