Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 4: Spintronics: Nanostructures and Optics

HL 4.8: Vortrag

Montag, 7. März 2016, 11:45–12:00, H13

Elliott-Yafet spin relaxation revisited — •Svenja Vollmar^{1, 2} and Hans Christian Schneider¹ — ¹Department of Physics and Research Center of OPTIMAS, University of Kaiserslautern — ²Graduate School of Excellence Materials Science in Mainz

By computing the dynamics of the reduced electronic density matrix, we present a new analysis of the Elliott-Yafet spin relaxation mechanism, i.e. the spin relaxation due to incoherent electron-phonon scattering [1,2,3]. In our approach spin dynamics is described correctly without approximating mixed spin states by pure spin states, as done in Yafet’s original treatment [3]. Our approach is therefore also valid for pronounced spin mixing. The central new quantity introduced in our calculation is a torque matrix element that determines the spin dynamics in a transparent fashion.

For the special case of Kramers degenerate bands we use this result to derive a novel expression for the close-to-equilibrium spin relaxation-time. To this end, we determine the reduced density matrix for a spin polarized system with arbitrary spin mixing in quasi-equilibrium [4].
[1] A. W. Overhauser, Phys. Rev. 89, 689 (1953).
[2] R. J. Elliott, Phys. Rev. 96, 266 (1954).
[3] Y. Yafet, Solid State Physics 14, 1 (1963).
[4] A. Baral, S. Vollmar, S. Kaltenborn, H.C. Schneider, arXiv: 1505.01432.