Abstract
Spin quantum beat spectroscopy is employed to investigate the in-plane anisotropy of the spin dynamics in (001) GaAs/AlGaAs quantum wells induced by an external electric field. This technique allows the anisotropy of the spin relaxation rate and the electron Landé factor to be measured simultaneously. The measurements are compared to similar data from (001) GaAs/AlGaAs quantum wells with applied shear strain and asymmetric barrier growth. All of these operations act to reduce the symmetry compared to that of a symmetric (001) quantum well in an identical manner (D C). However, by looking at the anisotropy of both and simultaneously we show that the microscopic actions of these symmetry breaking operations are very different. The experiments attest that although symmetry arguments are a very useful tool to identify the allowed spin dependent properties of a material system, only a microscopic approach reveals if allowed anisotropies will manifest.
- Received 21 December 2012
DOI:https://doi.org/10.1103/PhysRevB.87.075304
©2013 American Physical Society