Dresden 2009 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 12: Spin controlled transport I
HL 12.3: Talk
Tuesday, March 24, 2009, 10:00–10:15, BEY 81
Electrical triggering of phase-coherent spin packets by pulsed electrical spin injection across an Fe/GaAs Schottky contact — •C. Schwark1,2, I. Burkart1,2, J. Moritz1,2, L. Schreiber1,2, G. Güntherodt1,2, C. Adelmann3, C. Palmstrøm3,4, P.A. Crowell5, and B. Beschoten1,2 — 1Physikalisches Institut IIA, RWTH Aachen University, Templergraben 55, 52056 Aachen, and JARA-Fundamentals of Future Information Technology, Germany — 2Virtual Institute for Spin Electronics (ViSel), Aachen - Jülich - Göttingen — 3Department of Chemical Engineering and Material Science, University of Minnesota, Minneapolis 55455, USA — 4Departments of Electrical and Computer Engineering and Materials, University of California, Santa Barbara, CA 93106, USA — 5School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
Efficient electrical spin injection from a ferromagnet into a semiconductor has been demonstrated for various material systems by steady-state experiments. Here, we introduce a novel time-resolved technique based on electrical pumping and optical probing. Coherent spin packets are injected from an Fe layer through a reverse biased Schottky barrier into an n-GaAs layer by applying ultrafast current pulses at low temperature (20K). Spin coherence is probed by time-resolved Faraday rotation. Based on this technique we are able to observe multiple Larmor precessions and spin dephasing times greater than 50ns.
Work supported by BMBF, HGF and DFG.