Correlation between morphology and electron spin relaxation time in GaAs/AIGaAs quantum wells on misoriented GaAs(110) substrates

摘要

We investigated the correlation between morphology and electron spin relaxation time in GaAs/ AlGaAs multiple quantum wells (MQWs) on misoriented GaAs(l 10) substrates. For the MQW on a 2°-misoriented GaAs(110), formation of wide (110) step terraces due to step bunching was observed. Measurements of the temperature dependence of the electron spin relaxation time tv showed that the D'yakonov-PereP (DP) spin relaxation was suppressed even in the MQW on the 2°-misoriented GaAs(110) owing to the step terrace formation. In contrast, in the MQW on a 5°-misoriented GaAs(110), in which the surface showed ripple patterns, the t, became shorter than that on the on-axis GaAs(110), which we attribute to the enhanced electron spin relaxation originating from the bulk inversion asymmetry term in the DP mechanism that is induced by the substrate misorientation.