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arXiv · 1604.01559

Strong spin-orbit fields and Dyakonov-Perel spin dephasing in supported metallic films

Nguyen H. Long·Phivos Mavropoulos·David S. G. Bauer·Bernd Zimmermann·Yuriy Mokrousov·Stefan Blügel
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Abstract

Spin dephasing by the Dyakonov-Perel mechanism in metallic films deposited on insulating substrates is revealed, and quantitatively examined by means of density functional calculations combined with a kinetic equation. The surface-to-substrate asymmetry, probed by the metal wave functions in thin films, is found to produce strong spin-orbit fields and a fast Larmor precession, giving a dominant contribution to spin decay over the Elliott-Yafet spin relaxation up to a thickness of 70 nm. The spin dephasing is oscillatory in time with a rapid (sub-picosecond) initial decay. However, parts of the Fermi surface act as spin traps, causing a persistent tail signal lasting 1000 times longer than the initial decay time. It is also found that the decay depends on the direction of the initial spin polarization, resulting in a spin-dephasing anisotropy of 200% in the examined cases.

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Nguyen H. Long, Phivos Mavropoulos, David S. G. Bauer, Bernd Zimmermann, Yuriy Mokrousov, Stefan Blügel. 2016-04-06. Strong spin-orbit fields and Dyakonov-Perel spin dephasing in supported metallic films. https://doi.org/10.1103/physrevb.94.180406

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