Compensation effect on the CW spin-polarization degree of Mn-based structures

Abstract

We investigated the effects of Mn ions on the spin dynamics of electrons confined in a semiconductor quantum well nearby a Mn-based ferromagnetic layer. Circularly polarized Hanle and time-resolved photoluminescence (PL) measurements were carried out on a set of samples with different Mn delta-doping concentrations. We observe a strong influence of the Mn layer for both the electron lifetime and its spin-relaxation time for high-Mn concentrations, when the electrons significantly overlap with Mn ions. Our results also show that the circular-polarization degree obtained by simple continuous-wave PL measurements is not sufficient to determine the relaxation dynamics due to a compensation effect of the lifetime and the spin-relaxation time.