Spin relaxation in charged InAs/GaAs quantum dots

Abstract

Photoexcited electron and hole spin relaxation has been studied in modulation doped InAs/GaAs self-assembled quantum dots by means of time resolved photoluminescence. The electron spin relaxation times of 50 to 70 ps have been found for the undoped and p-doped samples, while the hole spins randomise on a much shorter time scale. Electrons preserve their spin orientation during capture and relaxation for excitation into the barriers, however, no preferential spin polarisation has been detected for carrier excitation directly into the dots