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arXiv · 1406.2715

Weak Localization, Spin Relaxation, and Spin-Diffusion: The Crossover Between Weak and Strong Rashba Coupling Limits

Yasufumi Araki·Guru Khalsa·Allan H. MacDonald
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Abstract

Disorder scattering and spin-orbit coupling are together responsible for the diffusion and relaxation of spin-density in time-reversal invariant systems. We study spin-relaxation and diffusion in a two-dimensional electron gas with Rashba spin-orbit coupling and spin-independent disorder, focusing on the role of Rashba spin-orbit coupling in transport. Spin-orbit coupling contributes to spin relaxation, transforming the quantum interference contribution to conductivity from a negative weak localization (WL) correction to a positive weak anti-localization (WAL) correction. The importance of spin channel mixing in transport is largest in the regime where the Bloch state energy uncertainty $\hbar/\tau$ and the Rashba spin-orbit splitting $\Delta_\mathrm{SO}$ are comparable. We find that as a consequence of this spin channel mixing, the WL-WAL crossover is non-monotonic in this intermediate regime, and use our results to address recent experimental studies of transport at two-dimensional oxide interfaces.

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Yasufumi Araki, Guru Khalsa, Allan H. MacDonald. 2014-06-10. Weak Localization, Spin Relaxation, and Spin-Diffusion: The Crossover Between Weak and Strong Rashba Coupling Limits. https://doi.org/10.1103/physrevb.90.125309

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