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Spin polarization control by electric field gradients

Dan Csontos·Sergio E. Ulloa
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Abstract

We show that the propagation of spin polarized carriers may be dramatically affected by {\em inhomogeneous} electric fields. Surprisingly, the spin diffusion length is found to strongly depend on the sign and magnitude of electric field \emph{gradients}, in addition to the previously reported dependence on the sign and magnitude of the electric field [Yu & Flatté, Phys. Rev. B {\bf 66}, 201202(R) 2002; {\em ibid.} {\bf 66}, 235302 (2002)]. This indicates that purely electrical effects may play a crucial role in spin polarized injection, transport and detection in semiconductor spintronics. A generalized drift-diffusion equation that describes our findings is derived and verified by numerical calculations using the Boltzmann transport equation.

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Dan Csontos, Sergio E. Ulloa. 2007-01-25. Spin polarization control by electric field gradients. https://doi.org/10.1103/physrevb.74.155207

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