Regensburg 2022 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 26: Quantum Dots and Wires 5: Optics 2
HL 26.8: Vortrag
Donnerstag, 8. September 2022, 11:45–12:00, H32
Internal Photoeffect from a Single Quantum Emitter — Pia Lochner1, Jens Kerski1, Annika Kurzmann2, Hendrik Mannel1, •Marcel Zöllner1, Andreas D. Wieck3, Arne Ludwig3, Martin P. Geller1, and Axel Lorke1 — 1University of Duisburg-Essen and CENIDE, Germany — 2RWTH Aachen University, Germany — 3Ruhr-University Bochum, Germany
As quantum information technologies require long spin coherence times in qubits and highly indistinguishable photons [1], we present a new and mostly neglected mechanism in self-assembled quantum dots that fundamentally limits the coherence times in optical quantum devices. By time-resolved resonance fluorescence (RF) measurements on a single quantum dot, we demonstrate an internal photoeffect [2] that emits electrons from the dot by an intra-band excitation. While the tunneling rate of an electron into the quantum dot is constant for increasing non-resonant laser intensity, the emission rate by the photoeffect increases linearly with increasing excitation intensity. This way, the emission rate is tunable over several orders of magnitude by adjusting the non-resonant laser excitation intensity.
Our findings show that a process, which is well known in single atom spectroscopy (i.e. photo ionization) can also be observed for a solid-state quantum emitter and has to be avoided or reduced to push the limits towards long qubit coherence times.
[1] T. D. Ladd et al., Nature 464, 45-53 (2010)
[2] P. Lochner et al., Phys. Rev. B 103, 075426 (2021)