Regensburg 2010 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 31: Poster I: Devices, Quantum Dots and Quantum Wires

HL 31.38: Poster

Tuesday, March 23, 2010, 18:30–20:30, Poster D1

Optical manipulation of a Mn spin in a quantum dot via light hole exciton transitions — •Doris E. Reiter¹, Giselmar Hemmert¹, 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 coherent manipulation of a single spin is of great interest in the field of quantum computing. One very promising candidate for an ultra fast spin manipulation is a single Mn spin doped into a single semiconductor quantum dot. The goal is an all-optical manipulation of the Mn spin, which becomes possible via the optical manipulation of the quantum dot exciton. The exciton couples to the Mn via a strong exchange interaction. When transitions of the heavy hole excitons are considered, only a spin transfer from the electron to the Mn spin is possible, while the heavy hole is pinned. In contrast, if light hole excitons are excited both electron and hole can transfer spin to the Mn, which opens up the possibility for an efficient spin control. In this contribution different switching schemes for a coherent manipulation of the Mn spin in a CdTe quantum dot are presented either to address well defined eigenstates or create coherent superposition states. Two different kinds of dots are studied. In a neutral dot the Mn spin can be changed by two while excitons are only in the system during the switching. In a negatively charged dot an inversion of the Mn spin can be achieved. The optical signal in a pump probe setup should be well suited to monitor the dynamics of the Mn spin.