Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 48: Poster 2

HL 48.58: Poster

Donnerstag, 26. März 2009, 15:00–17:30, P2

Theory of indirect spin dephasing in optically driven semiconductor quantum dots — •Anna Grodecka¹, Paweł Machnikowski², and Jens Förstner¹ — ¹Computational Nanophotonics Group, Theoretical Physics, University Paderborn, Paderborn, Germany — ²Institute of Physics, Wrocław University of Technology, Wrocław, Poland

Optically driven spin control schemes in quantum dot (QD) systems exploiting spin dependent charge evolution are considered as the most promising candidates for quantum computers. We show that even in the absence of direct spin-reservoir coupling, the spin state of a confined carrier in QD can undergo dephasing. The indirect dephasing process is studied in detail for specific optical spin control protocols using off-resonant trion excitations in doped semiconductor QDs [1,2]. The microscopic description of the interaction between charges and their phonon reservoir as well as its non-Markovian nature is included. Moreover, the decoherence channels resulting from radiative decay of the trion and imperfections of an adiabatic evolution are discussed.
1. A. Grodecka, C. Weber, P. Machnikowski, and A. Knorr, Phys. Rev. B 76, 205305 (2007).
2. A. Grodecka, P. Machnikowski, and J. Förstner, arXiv:0811.2108 (2008).