Regensburg 2004 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 41: Spinabh
ängiger Transport II
HL 41.4: Vortrag
Donnerstag, 11. März 2004, 16:00–16:15, H17
Large spin splittings in GaSb/AlSb heterostructures with absolute conduction minima deriving from the L valley — •Reinhard Scholz1, Jean-Marc Jancu2, Giuseppe La Rocca2, and Paul Voisin3 — 1Institut für Physik, Technische Universität Chemnitz — 2Scuola Normale Superiore and INFM, Pisa — 3Laboratoire de Photonique et de Nanostructures, CNRS, Marcoussis
Recently, it has been proposed to develop so-called spintronic devices based on spin-dependent properties in semiconductor nanostructures. The subsequent investigations of the spin splitting in semiconductor heterostructures have been focusing on quantized states resulting from the Γ valley of the conduction band in III-V compounds. Around Γ, the spin-orbit coupling is proportional to the Dresselhaus or k3 term in leading order, resulting in spin splittings of the order of 0.1 meV close to the Fermi energy in doped GaAs/AlAs heterostructures [1]. On the other hand, around the L point, k-linear spin-orbit coupling is allowed for the tranverse directions. For heterostructures with the absolute conduction minimum deriving from the L point of the bulk material, these k-linear terms result in large spin splittings for wave vectors orthogonal to the growth direction. Using narrow GaSb quantum wells between AlSb barriers as a model system with quantum well states related to the L valley, we demonstrate that spin splittings exceeding 10 meV can be achieved, more than 2 orders of magnitude above typical values resulting from the Dresselhaus term around the Γ point.
[1] J. Kainz, U. Rössler, and R. Winkler, Phys. Rev. B 68, 075322 (2003).