TY - CONF AU - Kleinjohann, Iris AU - Fischer, Andreas AU - Jäschke, Natalie AU - Anders, Frithjof B. TI - Optical Pumping of Electron Spins in Quantum Dot Ensembles VL - 50 CY - Jülich PB - Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag M1 - FZJ-2020-01428 T2 - Publication Series of the John von Neumann Institute for Computing (NIC) NIC Series SP - 247 - 254 PY - 2020 AB - 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. T2 - NIC Symposium 2020 CY - 27 Feb 2020 - 28 Feb 2020, Jülich (Germany) Y2 - 27 Feb 2020 - 28 Feb 2020 M2 - Jülich, Germany LB - PUB:(DE-HGF)8 ; PUB:(DE-HGF)7 UR - https://juser.fz-juelich.de/record/874418 ER -