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Acceptor bound spin polaron is estimated in a GaMnAs/GaAs quantum well using mean field approximation with the Brillouin function for different concentration of Mn ions. The spin polarization which is the free carrier two dimensional sheet concentration is calculated for the valence band holes. We present a theoretical study of diluted magnetic semiconductors treating the local p-d exchange interaction J between the itinerant carriers and the Mn electrons within a realistic band structure. [ABSTRACT FROM AUTHOR]

The donor impurity binding energy in CdTe / Cd1-xMnxTe QWW with square well confinement along x - direction and parabolic confinement along y - direction under the influence of externally applied magnetic field has been computed using variational principle in the effective mass approximation. The spin polaronic shift has also been computed. The results are presented and discussed. [ABSTRACT FROM AUTHOR]

We performed spin-resolved photoluminescence measurements on Ge/SiGe multiple quantum wells with different well thickness and using different exciting power densities. The polarization of the direct emission strongly depends on the relative weight of electrons photoexcited from the light and the heavy hole subbands. The study of the polarization as a function of the exciting power highlights the role of the carrier-carrier interactions in determining spin depolarization. [ABSTRACT FROM AUTHOR]

We report on time-resolved Kerr rotation (TRKR) experiments done on n-doped CdMnTe quantum wells (QWs), in the regime where strong coupling between the electron and the Mn spin-flip excitations shows up. It has been proposed previously to deduce the 2D electron gas spin susceptibility from the coupling energy between these spin excitations. Here we measure the coupling energy on a high mobility sample down to very low excitation density, and compare the results with spin-flip Raman scattering (SFRS) on the same sample. The electron spin polarizations measured by TRKR and SFRS are found in relatively good agreement. However the spin susceptibility measured by TRKR exceeds systematically the values predicted by many-body theory. This could be an indication that the two-oscillator model used to describe mixed electron-Mn spin excitations needs to be improved. [ABSTRACT FROM AUTHOR]

We present the findings for the fractional quantum conductance of holes that is caused by the edge channels in the silicon nanosandwich prepared within frameworks of the Hall geometry. This nanosandwich represents the ultranarrow p-type silicon quantum well (Si-QW), 2 nm, confined by the d-barriers heavily doped with boron on the n-type Si (100) surface. The edge channels in the Si-QW plane are revealed by measuring the longitudinal quantum conductance staircase, Gxx, as a function of the voltage applied to the Hall contacts, Vxy, to a maximum of 4e²/h. In addition to the standard plateau, 2e²/h, the variations of the Vxy voltage appear to exhibit the fractional form of the quantum conductance staircase with the plateaus and steps that bring into correlation respectively with the odd and even fractions. [ABSTRACT FROM AUTHOR]

We performed cw-photoluminescence (PL) measurements on a 15 nm wide p-doped Al0.3Ga0.7As-GaAs-Al0.3Ga0.7As quantum well structure at low temperatures. By irradiating the sample with circularly polarized light and analyzing the degree of circular polarization of the PL signal, we found a significantly higher degree of spin polarization for charged excitons (trions) than for neutral excitons. Time-resolved pump-probe and Faraday-rotation experiments give an additional information concerning the exciton and trion resonant photoexcitation. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]