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HL: Fachverband Halbleiterphysik
HL 26: Quantum Dots and Wires 5: Optics 2
HL 26.10: Talk
Thursday, September 8, 2022, 12:15–12:30, H32
Auger-assisted electron spin-flips in a single quantum dot — •Hendrik Mannel1, Jens Kerski1, Pia Lochner1, Marcel Zöllner1, Fabio Rimek1, Arne Ludwig2, Andreas Wieck2, Axel Lorke1, and Martin Geller1 — 1Faculty of Physics and CENIDE, University of Duisburg-Essen, Duisburg, Germany — 2Chair of Applied Solid State Physics, Ruhr-University Bochum, Germany
A long electron spin coherence lifetime is the key requirement for future solid-state spin qubits. However, for instance, in self-assembled quantum dots the coupling to nuclei, co-tunneling with a nearby reservoir, and spin-orbit coupling limit the spin-lifetime.
Using resonance fluorescence, we here demonstrate an additional fundamental process that can lead to a single electron spin-flip via an Auger recombination [1]. The quantum dot is placed in a magnetic field in Faraday geometry and charged with one (spin-up or spin-down) electron [2]. In time-resolved resonant fluorescence measurements and using a rate equation model, we can determine the Auger and spin-flip rates in a magnetic field.
Our results reveal an additional, so far neglected Auger-assisted spin-flip process: Auger recombination with subsequent electron tunneling from the reservoir. The present dot is weakly coupled to an electron reservoir. A strong coupling will enhance this Auger-assisted spin-flip rate and thus reveal an important mechanism limiting the spin lifetime due to a strong coupling to a nearby reservoir.
[1] A. Kurzmann et al., Nano Lett. 16, 3367 (2016). [2] J. Dreiser et al., Phys. Rev. B 77, 075317 (2008).