Regensburg 2022 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 25: Poster 1

HL 25.94: Poster

Wednesday, September 7, 2022, 18:00–20:00, P2

Spin noise spectroscopy of a single InGaAs quantum dot at high magnetic fields — •Kai Hühn, Pavel Sterin, Jens Hübner, and Michael Oestreich — Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstrase 2, 30167 Hannover, Germany

Single holes in InGaAs quantum dots hold great promise as potential qubits due to the slow relaxation of selected spin degrees of freedom. However, the impact of phonon induced spin relaxation and occupancy noise for high magnetic fields remained unclear so far. Here, we use the method of spin noise spectroscopy (SNS) to gain a detailed insight into such mechanisms and measure the spin and charge dynamics for magnetic fields up to 4T and temperatures between 1.8K and 10K. Here, we combine, the quasi non-disturbant measurement scheme of SNS with an extrapolation to truly zero disturbance of the QD system. We find that the total noise power originates not just only from the hole-spin but from several processes including the relaxation of the hole spin and the charge state dynamics of the QD due to Auger recombination. In addition, our measurements indicate a long term stability of the intrinsic hole spin life time on the order of months. We compare our results with theoretical calculations which explicitly address one and two phonon processes as the limiting mechanism of the intrinsic hole spin relaxation.