Long-lived nanosecond spin coherence in high-mobility 2DEGs confined in double and triple quantum wells

TL;DR

This study demonstrates long-lived nanosecond spin coherence in high-mobility 2DEGs within multilayer GaAs quantum wells, achieved by tailoring spin-orbit interactions through structural and electronic parameters, supporting spintronic device development.

Contribution

It presents a method to achieve long spin dephasing times in multilayer quantum wells by controlling spin-orbit interactions via sample parameters.

Findings

Nanosecond spin dephasing times achieved in multilayer GaAs quantum wells.

Spin coherence maintained in high-mobility 2DEGs beyond the metal-insulator transition.

Correlation between scattering times and spin polarization decay supports spintronic applications.

Abstract

We investigated the spin coherence of high-mobility two-dimensional electron gases confined in multilayer GaAs quantum wells. The dynamics of the spin polarization was optically studied using pump-probe techniques: time-resolved Kerr rotation and resonant spin amplification. For double and triple quantum wells doped beyond the metal-to-insulator transition, the spin-orbit interaction was tailored by the sample parameters of structural symmetry (Rashba constant), width and electron density (Dresselhaus linear and cubic constants) which allows us to attain long dephasing times in the nanoseconds range. The determination of the scales: transport scattering time, single-electron scattering time, electron-electron scattering time, and spin polarization decay time further supports the possibility of using n-doped multilayer systems for developing spintronic devices.