2006/12/31 by D. Stich, Dominik Stich, J. Zhou +9 · 4 citations
Engineering · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Semiconductor materials and devices #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.98.176401
published as Phys. Rev. Lett. 98, 176401 (2007) · 4 pages, 4 figures, to be published in PRL
arxiv created 2007/03/28 · openalex publication_date 2007/04/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We have investigated the spin dynamics of a high-mobility two-dimensional electron system (2DES) in a GaAs\mathrm\text\ensuremath-Al0.3Ga0.7As single quantum well by time-resolved Faraday rotation in dependence on the initial degree of spin polarization, P, of the 2DES. From P\ensuremath∼0 to P\ensuremath∼30%, we observe an increase of the spin dephasing time, T2*, by an order of magnitude, from about 20 ps to 200 ps, in good agreement with theoretical predictions by Weng and Wu [Phys. Rev. B 68, 075312 (2003)]. Furthermore, also the electron g factor is found to decrease for increasing P. Fully microscopic calculations reproduce the most salient features of the experiments, i.e., a dramatic decrease of spin dephasing and a moderate decrease of the electron g factor with increasing P. We show that both results are determined dominantly by the Hartree-Fock contribution of the Coulomb interaction.