Published by the AIP PublishingArticles you may be interested in Effect of low-temperature annealing on the electronic-and band-structures of (Ga,Mn)As epitaxial layers Quantitative analysis of the angle dependence of planar Hall effect observed in ferromagnetic GaMnAs film J. Appl. Phys. 105, 07C501 (2009); 10.1063/1.3055354Vanishing of ferromagnetic order in (Ga,Mn)As films at high hole concentrations: beyond the mean field Zener model

We investigated time-resolved differential reflection in GaMnAs by pump-probe method at various wavelengths. The signals in GaMnAs were found to be more influenced by the compensating nature of the samples, rather than by the Mn concentrations. The time-resolved reflectivity of highly compensated samples exhibited stronger negative ∆R component at photon energies higher than the bandgap energy. This behaviour was similar to that of As + -ion implanted GaAs. Our results suggest that arsenic antisites (As Ga ) act as deep donors as in low-temperature grown GaAs and play an important role in compensating holes in GaMnAs.

Nearly complete spin polarization (SP) of carriers was observed in photoluminescence (PL) experiments on CdSe self-assembled quantum dots (QDs) embedded in ZnMnSe at 5 K in magnetic fields above 1 T. The redshift of the PL from CdSe QDs in the presence of the magnetic field was less than that of ZnMnSe, but still sufficiently large to account for the high SP. At low fields, however, the SP of carriers in CdSe QDs is observed to be smaller than in the surrounding ZnMnSe. This, along with time-resolved PL data, suggests that the SP in CdSe QDs is mainly due, not to the injection of SP carriers from ZnMnSe, but rather due to the Zeeman splitting of internal QD states.