Berlin 2005 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 21: Spintronik III

HL 21.1: Vortrag

Samstag, 5. März 2005, 10:45–11:00, TU P164

Spin lifetimes at GaAs (100) and (110) surfaces — •Jan-Peter Wüstenberg, Lijun Guo, Kevin Hiebbner, Hans-Christian Schneider, Michael Bauer, and Martin Aeschlimann — FB Physik, TU Kaiserslautern, Erwin-Schrödinger-Str., 67663 Kaiserslautern

Spin transport through a semiconductor/metal interface is an important obstacle in semiconductor-based spintronics. At semiconductor surfaces the Fermi-level pinning may cause a band bending that significantly affects the carrier and spin dynamics. The decay of the electron-spin polarization near different p-doped GaAs surfaces is investigated by means of time- and spin-resolved two photon photoemission (TR-2PPE). By measuring the spin and energy of electrons emitted from the different GaAs surfaces the (energy-dependent) spin-polarization decay times are determined. The experimental results are compared to bulk measurements (time-resolved magneto-optical Kerr effect) and theoretical results for spin-polarization decay within the Bir-Aronov-Pikus mechanism. It is found that the strength of the band bending at the surfaces directly influences the spin decay.