Origin of Magnetic Circular Dichroism in GaMnAs: Giant Zeeman Splitting versus Spin Dependent Density of States

Abstract

We present a unified interpretation of experimentally observed magnetic circular dichroism (MCD) in the ferromagnetic semiconductor (Ga,Mn)As, based on theoretical arguments, which demonstrates that MCD in this material arises primarily from a difference in the density of spin-up and spin-down states in the valence band brought about by the presence of the Mn impurity band, rather than being primarily due to the Zeeman splitting of electronic states.

Magneto-optical Kerr spectroscopy of (Ga,Mn)(As,P) ferromagnetic layers: Experiments and k.p theory

“…41,[58][59][60] Competing with this hypothesis, the impurity-band model predicts that the Fermi level resides inside the Mn impurity band detached from the GaAs VB. [14][15][16][61][62][63] In this case, the ferromagnetism spreads within this impurity band by a hopping effect without affecting the VB holes. In our approach, we have assumed that the Fermi level is located within the VB.…”

“…In the ferromagnetic SC (Ga,Mn)As, MO spectroscopy in the visible and infrared spectral regions has been used to gain insight into the controversial issue of the energy position of the Fermi level, inside the valence band (VB) or in an impurity band detached from the VB. [11][12][13][14][15][16] The prediction and experimental determination of MO spectra are also of prime importance to select the optimal wavelength for the optical investigation of static and dynamical magnetic properties. Optically detected hysteresis cycles obtained from the MOKE provide information on the magnetic anisotropy and magnetization reversal processes.…”

“…6,18,19 Magneto-optical microscopy uses the MOKE to gain insight into the magnetic domains static pattern 7,20,21 and the domain wall dynamics. 22 While the MO effects in (Ga,Mn)As have been extensively investigated, [13][14][15][16][23][24][25][26][27][28][29][30][31][32][33][34] the MO properties of (Ga,Mn) (As,P) thin films, more specifically the interplay between the Mn doping and P substitution, remain to be investigated. Hence, in the present study, we report on the MOKE in the interband transition range for ferromagnetic (Ga,Mn)(As,P) samples with different P and Mn contents.…”

Управление циркулярной поляризацией электролюминесценции в спиновых светоизлучающих диодах на основе гетероструктур InGaAs/GaAs/delta<Mn>

“…Рассчи-танная в экспериментах величина N 0 β является, как пра-вило, усредненной по большому количеству примесных атомов [12]. Таким образом, изменение знака спиновой поляризации дырок и P EL мы связываем именно с варьированием знака N 0 β. Общепринятой конфигураци-ей Mn в GaAs является A 0 (3d 5 + дырка), такая кон-фигурация обеспечивает ферромагнитное упорядочение между ионами Mn и носителями [14][15][16]. Такая " обыч-ная" конфигурация, вероятно, обусловливает " положи-тельный" знак поляризации.…”

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing

“…[11][12][13][14][15] Realizing such applications requires a good understanding of the fundamental properties of these materials; however, the large density of defects associated with their growth at low temperatures (essential for the substitutional incorporation of magnetic dopants such as Mn) severely complicates the theoretical treatment of exchange coupling and ferromagnetic order [16][17][18] . These defects also impede the interpretation of transport and linear optical experiments on these materials [19][20][21][22][23][24] .…”