Dresden 2011 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 43: TR: Nanoelectronics II - Spintronics and Magnetotransport 2 (jointly with HL and MA)
TT 43.4: Talk
Wednesday, March 16, 2011, 19:45–20:00, HSZ 03
Relaxation mechanisms of the Persistent Spin Helix — •Matthias C. Lüffe1, Janik Kailasvuori2, and Tamara S. Nunner1 — 1Fachbereich Physik & Dahlem Center for Complex Quantum Systems, FU Berlin, Germany — 2MPI für Physik komplexer Systeme, Dresden, Germany
The Persistent Spin Helix has been predicted and recently observed as an unusually long-lived helical texture of spin polarization in a semiconductor quantum well where the Rashba- and linear Dresselhaus spin-orbit couplings are of equal strengths. In order to understand the decay in time of this object, we derive and solve semiclassical spin diffusion equations which take spin-dependent impurity scattering, cubic Dresselhaus spin-orbit coupling and, in particular, electron--electron interactions into account. We find that for reported experimental parameters the temperature-dependent lifetime of the persistent spin helix is largely determined by the interplay of cubic Dresselhaus spin-orbit coupling and electron--electron interactions. On the basis of this insight we propose for an experimental starting point a spatially damped spin profile which then evolves towards a truly persistent spin helix even in the---to some extent unavoidable---presence of cubic Dresselhaus spin-orbit interactions.