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arXiv · 1008.0132

Random walk approach to spin dynamics in a two-dimensional electron gas with spin-orbit coupling

Luyi Yang·J. Orenstein·Dung-Hai Lee
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Abstract

We introduce and solve a semi-classical random walk (RW) model that describes the dynamics of spin polarization waves in zinc-blende semiconductor quantum wells. We derive the dispersion relations for these waves, including the Rashba, linear and cubic Dresselhaus spin-orbit interactions, as well as the effects of an electric field applied parallel to the spin polarization wavevector. In agreement with fully quantum mechanical calculations [Kleinert and Bryksin, Phys. Rev. B \textbf{76}, 205326 (2007)], the RW approach predicts that spin waves acquire a phase velocity in the presence of the field that crosses zero at a nonzero wavevector, $q_0$. In addition, we show that the spin-wave decay rate is independent of field at $q_0$ but increases as $(q-q_0)^2$ for $q\neq q_0$. These predictions can be tested experimentally by suitable transient spin grating experiments.

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Luyi Yang, J. Orenstein, Dung-Hai Lee. 2011-03-30. Random walk approach to spin dynamics in a two-dimensional electron gas with spin-orbit coupling. https://doi.org/10.1103/physrevb.82.155324

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