Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 42: Optical Properties of Quantum dots: Theory and Simulation
HL 42.8: Vortrag
Donnerstag, 28. Februar 2008, 11:30–11:45, EW 201
Optical Spin Switching in a Quantum Dot with a Single Mn Atom — •Doris E. Reiter1, Vollrath Martin Axt2, and Tilmann Kuhn1 — 1Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Str.10,48149 Münster — 2Institut für Theoretische Physik III, Universität Bayreuth, 95440 Bayreuth
Spins in semiconductor quantum dots are promising candidates as basic ingredients for new quantum hardware, e.g. magnetic bits. In a single quantum dot with a single Mn atom as has been fabricated recently the spin of the Mn instead of the exciton spin can be used as new basis for spintronics. The Mn spin has six possible orientations. In contrast to the carrier spins however it is not directly accessible by laser light. Instead, it can be controlled via the exciton, which can be driven by the optical excitation with ultra short laser pulses. Exciton and Mn spin couple to each other via direct exchange interaction. Though stronger coupled, the heavy holes can hardly induce spin flips, but electrons and light holes have great impact on the dynamics of the Mn spin. Starting from an initial state, we show that the Mn spin states can be selectively accessed via flips on ultrashort times scales induced by a sequence of laser pulses.