Finite-Size Effect in Phonon-Induced Elliott-Yafet Spin Relaxation in Al

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Finite-Size Effect in Phonon-Induced Elliott-Yafet Spin Relaxation in Al

J. D. Watts, J. T. Batley, N. A. Rabideau, J. P. Hoch, L. O’Brien, P. A. Crowell, and C. Leighton

Phys. Rev. Lett. 128, 207201 – Published 17 May 2022

Abstract

The Elliott-Yafet theory of spin relaxation in nonmagnetic metals predicts proportionality between spin and momentum relaxation times for scattering centers such as phonons. Here, we test this theory in Al nanowires over a very large thickness range (8.5–300 nm), finding that the Elliott-Yafet proportionality “constant” for phonon scattering in fact exhibits a large, unanticipated finite-size effect. Supported by analytical and numerical modeling, we explain this via strong phonon-induced spin relaxation at surfaces and interfaces, driven in particular by enhanced spin-orbit coupling.

Received 11 December 2021
Accepted 31 March 2022

DOI:https://doi.org/10.1103/PhysRevLett.128.207201

Physics Subject Headings (PhySH)

Spintronics

Metals

Transport techniques

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

J. D. Watts ^1,2, J. T. Batley², N. A. Rabideau ², J. P. Hoch ², L. O’Brien ^2,3, P. A. Crowell¹, and C. Leighton ^2,*

¹School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
²Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
³Department of Physics, University of Liverpool, Liverpool L69 3BX, United Kingdom