Erschienen in:Jülich : Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag, Publication Series of the John von Neumann Institute for Computing (NIC) NIC Series 50, 247 - 254 (2020). ; NIC Symposium 2020 ; NIC Symposium 2020 NIC Symposium 2020, Jülich, Germany, 2020-02-27 - 2020-02-28
Sprache:
Englisch
Entstehung:
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Beschreibung:
We use the central spin model to analyse optical pumping of singly charged quantum dots. An exact quantum mechanical approach is employed to calculate the impact of several million laser pulses. The periodical excitation imprints on the system and the electron spin polarisation refocuses directly before each pulse. Our calculations link the non-monotonic behaviour of the revival amplitude as function of the external magnetic field found in experiments to the nuclear Larmor precession. Furthermore, we extend our model to a cluster of coupled central spin models to investigate long-range spin-spin interactions in quantum dot ensembles. A semiclassical approach handles the large amount of spins. By means of the cluster approach, we provide an understanding of the electron spin dephasing at different external magnetic fields and spectral widths of the optical excitation. Our model reveals the counterbalancing effects generating a constant dephasing time in dependence of the spectral laser width in experiment.