Zeeman Splitting of Ferromagnetic GaMnAs on InP Observed by Magnetic Circular Dichroism in Reflection Mode

Systematic investigations of Ga 1− x Mn x As grown on InP with different Mn concentrations have been conducted using magnetic circular dichroism (MCD) in reflection mode. The MCD spectrum of Ga 0.97 Mn 0.03 As/InP was decomposed into two dispersion curves originating from E 1 and E 1 + Δ 1 optical transitions using the energy derivative of a Gaussian function. The Zeeman splitting energy E 1 at the L critical point (0.6 meV) of ferromagnetic Ga 0.97 Mn 0.03 As/InP was estimated using a rigid band shift model. Based on the relationship between E 1 and E 0 (Γ critical point) observed in Cd 1− x Mn x Te dilute magnetic semiconductor (DMS), the Zeeman splitting energy E 1 (9.6 meV) of ferromagnetic Ga 1− x Mn x As/InP was calculated. In addition, it was established that the peaks in the MCD spectra at L critical points shift toward the lower energy side as the Mn concentration is increased, and the observed shift saturates for Mn content of x = 0.001. Furthermore, the measured absorption spectra for Ga 1− x Mn x As/InP did not show noticeable peak shifts with increasing Mn content. This suggests that the s , p – d exchange interaction induced in Ga 1− x Mn x As/InP has localized nature due to the presence of a Mn rigid sphere of influence.