2003/09/30 by W. O. Putikka, Robert Joynt, R. Joynt · 5 citations
Physics and Astronomy · #Magnetic properties of thin films #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.70.113201
4 pages, 2 figures; revised version has a more complete discussion of the Elliott-Yafet and spin-phonon decay mechanisms
arxiv created 2004/05/13 · openalex publication_date 2004/09/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Time-resolved measurements of magnetization in n\text\ensuremath-GaAs have revealed a rich array of spin decoherence processes, and have shown that fairly long lifetimes (\ensuremath∼100\phantom\rule0.3em0exns) can be achieved under certain circumstances. In time-resolved Faraday rotation and time-resolved Kerr rotation the evolution of the magnetization can be followed as a function of temperature, applied field, doping level, and excitation level. We present a theory for the spin relaxation in n\text\ensuremath-GaAs based on a set of rate equations for two interacting thermalized subsystems of spins: localized states on donor sites and itinerant states in the conduction band. The conduction-band spins relax by scattering from defects or phonons through the D'yakonov-Perel' mechanism, while the localized spins relax by interacting with phonons (when in an applied field) or through the Dzyaloshinskii-Moriya interaction. In this model, numerous features of the data, including puzzling temperature and doping dependencies of the relaxation time, find an explanation.