Dresden 2009 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 48: Poster 2
HL 48.61: Poster
Thursday, March 26, 2009, 15:00–17:30, P2
Optical spin switching in a Mn doped QD under influence of a magnetic field — •Doris E. Reiter1, Vollrath Martin Axt2, and Tilmann Kuhn1 — 1Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 10, 48149 Münster — 2Theoretische Physik III, Universität Bayreuth, 95440 Bayreuth
The combination of semiconducting and ferromagnetic materials has interesting possible applications in the field of spintronics. In a CdTe quantum dot doped with a single Mn atom the exciton line in photoluminescence spectra splits into six lines clearly demonstrating the strong exchange interaction between the exciton and the Mn spin. As we have shown recently the Mn spin state can be controlled in an indirect optical way by a sequence of laser pulses, which create, destroy or manipulate excitons in the system. Thus the Mn spin can be driven from a given initial value into all the other spin states. By adding a magnetic field in Faraday configuration the efficiency of this process can be strongly enhanced and the total switching time can be reduced from 100 ps to about 40 ps, when dark and bright excitons are brought to resonance. The timescales for the switching process are of the order of the lifetime of the bright exciton. Therefore we consider a model which includes radiative decay in terms of a decay time. In this contribution we discuss the influence of the finite lifetime of the exciton as well as the influence of magnetic fields on the optical switching process.