The effects of quantum confinement on electron spin g-factor have been investigated in lattice-matched GaAs/AlGaAs quantum wells (QWs) and strained InGaAs/GaAs QWs. We demonstrate how the spin precession frequency changes depending on the GaAs well width and the indium fraction in In x Ga 1-x As well by time-resolved photoluminescence measurements under a high magnetic field. The g-factor values obtained by the spin precession measurements are compared with precise calculation method proposed by Ivchenko. The calculated results agree with our experimental results in lattice matched QWs. In addition to this calculation, we have examined a simplified k·p perturbation calculation. It is found that the k·p calculation exhibits good agreement with the experimental trends both in the unstrained and strained QW systems.

We report on spin precession observed in CdTe and GaAs bulks at room temperature by means of time‐resolved Kerr rotation measurements under a high magnetic field. Electron g‐factor in CdTe obtained from the spin precession measurements was significantly different from that in GaAs having similar band gap because of stronger spin‐orbital interaction in CdTe. Theoretical analysis on temperature dependence of the g‐factor was also conducted, based on 3‐band k·p perturbation theory, to estimate the effects of remote bands other than the 3 bands. The dependence of the electron g‐factor on temperature was numerically reproduced in low temperature region by considering thermal distribution of electrons. The effects of the remote bands are discussed in relation to the discrepancy between experiments and theoretical analysis in higher temperature region. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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The effects of quantum confinement on electron g-factor tensor components, g ? and g k , were investigated for a wide variety of GaAs/ Al x Ga 1Àx As quantum well structures, including the weak confinement regime, to determine the mapping of the g-factor components as functions of the aluminum content of an Al x Ga 1Àx As barrier and GaAs well thickness. The g-factor components were determined from the periods of electron spin precession, which were assessed by polarization-and time-resolved photoluminescence measurements under a magnetic field. The measured transverse component g ? was found to depend substantially on the barrier aluminum content, while the longitudinal component g k was insensitive to the aluminum content. In addition to the experiments, the electron g-factor was analyzed theoretically on the basis of the three-band kÁp perturbation theory by using Kiselev's method. Comparison of the experimental and theoretical results demonstrates that the three-band kÁp calculation is sufficient to reproduce the main features of the experimental results including the effects of the barrier aluminum content.

Room temperature gate modulation of electron spin relaxation time in (110)-oriented GaAs/AlGaAs quantum wells Appl. Phys. Lett. 97, 202102 (2010); 10.1063/1.3514675 Roles of the bias fields in the exchange interaction between the electron and hole spins in quantum wells Intersubband exchange interaction induced by optically excited electron spins in GaAs/AlGaAs quantum wells Appl. Phys. Lett. 94, 162104 (2009); 10.1063/1.3118584Room temperature electron spin coherence in telecom-wavelength quaternary quantum wells Electron spin-spin interaction in an asymmetric coupled quantum well (CQW) was investigated through electron spin-precession measurements. Precession (Larmor) frequencies from electrons localized in two CQWs were measured by means of polarization-and time-resolved photoluminescence measurements under a high magnetic field. At a low excitation power density, the Larmor frequency of the CQW was same as that of a single quantum well. The Larmor frequency of electron spin in one well was shifted to that in the other well as the excitation power density was increased. These experimental results are quantitatively explained by an exchange interaction between electrons localized in the two wells.