Full Electrical Control of the Electron Spin Relaxation in GaAs Quantum Wells

TL;DR

This paper demonstrates full electrical control over electron spin relaxation times in GaAs quantum wells, achieving over 30 ns by tuning spin-orbit interactions with an external electric field.

Contribution

It shows how to electrically manipulate electron spin relaxation in GaAs quantum wells by balancing Rashba and Dresselhaus effects, enabling precise spin control.

Findings

Spin relaxation time exceeds 30 ns under electric field.

Electric field tuning can nearly cancel spin-orbit splitting.

Simultaneous control of spin relaxation in three directions.

Abstract

The electron spin dynamics in (111)-oriented GaAs/AlGaAs quantum wells is studied by timeresolved photoluminescence spectroscopy. By applying an external field of 50 kV/cm a two-order of magnitude increase of the spin relaxation time can be observed reaching values larger than 30 ns; this is a consequence of the electric field tuning of the spin-orbit conduction band splitting which can almost vanish when the Rashba term compensates exactly the Dresselhaus one. The measurements under transverse magnetic field demonstrate that the electron spin relaxation time for the three space directions can be tuned simultaneously with the applied electric field.