Regensburg 2002 – scientific programme
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HL: Halbleiterphysik
HL 38: Poster 2
HL 38.64: Poster
Thursday, March 14, 2002, 16:30–19:00, Poster A
Spin splitting and spin relaxation time in semiconductor heterostructures — •Josef Kainz1, Ulrich Rössler1, and Roland Winkler2 — 1Institut für Theoretische Physik, 93040 Regensburg — 2Institut für Technische Physik III, Staudtstr. 7, 91058 Erlangen
Spin relaxation of electrons in (001)-AlAs/GaAs heterostructures is dominated by the Dyakonov-Perel mechanism according to which - in a simplified description - the spin-relaxation rate τs−1 is proportional to the square of the spin-splitting Δ E of the electron subband at the Fermi energy EF [1]. A more detailed analysis takes into account that Δ E is anisotropic due to the combined effects of bulk and surface induced asymmetry (BIA and SIA respectively) [1]. As a consequence the spin relaxation rate becomes a tensor, whose components are determined by the anisotropic subband spin splittings Δ E (k) , where k is the in-plane wave vector. We perform multiband-envelope function calculations [2] for different asymmetrically doped (001)-AlAs/GaAs quantum wells and determine from the anisotropic spin-splitting at EF the components of the relaxation rate tensor in dependence on quantum well width and carrier concentration.
[1] N. S. Averkiev and L. E. Golub, Phys. Rev. B 60, 15582 (1999).
[2] R. Winkler and U. Rössler, Phys. Rev. B 48, 8918 (1993).