Electrong-factor anisotropy in symmetric (110)-oriented GaAs quantum wells
We demonstrate by spin quantum beat spectroscopy that in undoped symmetric (110)-oriented GaAs/AlGaAs
single quantum wells, even a symmetric spatial envelope wave function gives rise to an asymmetric in-plane
electron Land´e g-factor. The anisotropy is neither a direct consequence of the asymmetric in-plane Dresselhaus
splitting nor a direct consequence of the asymmetric Zeeman splitting of the hole bands, but rather it is a pure
higher-order effect that exists as well for diamond-type lattices. The measurements for various well widths are
very well described within 14 × 14 band k·p theory and illustrate that the electron spin is an excellent meter
variable for mapping out the internal—otherwise hidden—symmetries in two-dimensional systems. Fourth-order
perturbation theory yields an analytical expression for the strength of the g-factor anisotropy, providing a
qualitative understanding of the observed effects.
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041301 (R)
041301 (R)
American Physical Society (APS)
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