Spin-sensitive Bleaching and Spin-Relaxation in QW's

TL;DR

This paper investigates how spin relaxation influences the saturation of infrared absorption in p-type GaAs quantum wells, revealing that narrower wells exhibit lower saturation intensities and providing experimental spin relaxation times.

Contribution

It demonstrates the dominant role of hole spin relaxation in absorption saturation and explores how quantum well width and temperature affect this process.

Findings

Saturation intensity decreases with narrower QWs.

Spin relaxation times are experimentally determined.

Absorption saturation is mainly controlled by hole spin relaxation.

Abstract

Spin-sensitive saturation of absorption of infrared radiation has been investigated in p-type GaAs QWs. It is shown that the absorption saturation of circularly polarized radiation is mostly controlled by the spin relaxation time of the holes. The saturation behavior has been investigated for different QW widths and in dependence on the temperature with the result that the saturation intensity substantially decreases with narrowing of QWs. Spin relaxation times were experimentally obtained by making use of calculated (linear) absorption coefficients for inter-subband transitions.