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Boundary spin Hall effect in a two-dimensional semiconductor system with Rashba spin-orbit coupling

Yaroslav Tserkovnyak·Bertrand I. Halperin·Alexey A. Kovalev·Arne Brataas
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Abstract

We derive boundary conditions for the coupled spin-charge diffusion equations at a transmitting interface between two-dimensional electron systems with different strengths of the Rashba spin-orbit (SO) coupling $α$, and an electric field parallel to the interface. We consider the limit where the spin-diffusion length l_s is long compared to the electron mean free path l, and assume that $α$ changes discontinuously on the scale of l_s. We find that the spin density is also discontinuous on the scale of l_s. In the case where the electron mobility is constant across the interface, this leads to the complete suppression of the expected spin injection from a region with $α\neq0$ into a non-SO region with $α=0$.

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Yaroslav Tserkovnyak, Bertrand I. Halperin, Alexey A. Kovalev, Arne Brataas. 2007-08-04. Boundary spin Hall effect in a two-dimensional semiconductor system with Rashba spin-orbit coupling. https://doi.org/10.1103/physrevb.76.085319

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