Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 48: Quantum Coherence and Quantum Information Systems (joint session TT/MA)

MA 48.4: Vortrag

Donnerstag, 15. März 2018, 16:00–16:15, H 2053

Semiclassical simulation of weakly coupled semiconductor quantum dots — •Andreas Fischer and Frithjof Anders — Technische Universität Dortmund, Lehrstuhl für Theoretische Physik II, 44227 Dortmund

In two-color pump-probe experiments one can excite distinct subsets of singly charged quantum dots independently by laser pulses of different photon energies. The optically oriented electron spins precess in an external magnetic field applied in Voigt geometry. Phase shifts, changing dephasing times and amplitude modulations in the signal depending on the pump configuration indicate a coherent interaction between the quantum dots. The experimental signatures can be reproduced by comprising two central spin models augmented by a Heisenberg interaction between the two central spins. The time evolution is calculated using a semiclassical approximation (SCA). To include the trion state excited by the pump pulses and the subsequent decay we combine the SCA with the quantum mechanical Lindblad equation. Our approach can be extended to multi-color pump-probe experiments.