Anisotropic Electron Spin Lifetime in (In,Ga)As/GaAs (110) Quantum Wells

TL;DR

This study investigates the anisotropic electron spin lifetimes in (In,Ga)As/GaAs (110) quantum wells, revealing a high anisotropy ratio that varies with quantum well width and In concentration, using time-resolved optical techniques.

Contribution

It provides the first detailed measurement of spin lifetime anisotropy in (110) quantum wells and compares it to (001) orientation, highlighting the effects of well dimensions and composition.

Findings

Anisotropy ratio of 480 observed in broadest quantum well.

Anisotropy increases with In concentration, aligning with theoretical predictions.

Spin lifetime anisotropy depends on quantum well width and strain conditions.

Abstract

Anisotropic electron spin lifetimes in strained undoped (In,Ga)As/GaAs (110) quantum wells of different width and height are investigated by time-resolved Faraday rotation and time-resolved transmission and are compared to the (001)-orientation. From the suppression of spin precession, the ratio of in-plane to out-of-plane spin lifetimes is calculated. Whereas the ratio increases with In concentration in agreement with theory, a surprisingly high anisotropy of 480 is observed for the broadest quantum well, when expressed in terms of spin relaxation times.