Berlin 2024 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 19: Quantum Dots and Wires: Optics I

HL 19.9: Vortrag

Dienstag, 19. März 2024, 12:00–12:15, EW 202

Swing-Up Dynamics in Quantum Emitter Cavity Systems: Near Ideal Single Photons and Entangled Photon Pairs — •Nils Heinisch, Nikolas Köcher, David Bauch, and Stefan Schumacher — Physics Department, CeOPP, and PhoQS, Paderborn University, Germany

In the SUPER scheme (Swing-UP of the quantum EmitteR population) excitation of a quantum emitter is achieved with two off-resonant, red-detuned laser pulses, as theoretically [1] and experimentally demonstrated [2,3]. In particular, this approach promises generation of high-quality single photons without the need of complex laser stray light suppression or careful spectral filtering. In the present work we extend this method to quantum emitters, specifically semiconductor quantum dots (QDs), inside a resonant optical cavity [4-6]. A significant advantage of the SUPER scheme is identified in that it eliminates re-excitation of the quantum emitter by suppressing photon emission during the excitation cycle via the AC-Stark effect. This, in turn, leads to almost ideal single photon purity, overcoming a major factor typically limiting the quality of photons generated with quantum emitters in high quality cavities. We further find that for cavity-mediated degenerate photon-pair generation from the QD biexciton the SUPER excitation does not spoil the polarization entanglement. [1] T. K. Bracht et al., PRX Quantum 2, 040354 (2021). [2] Y. Karli et al., Nano Letters 22, 6567 (2022). [3] K. Boos et al., arXiv:2211.14289 (2022). [4] N. Heinisch et al., arXiv:2303.12604 (2023). [5] L. Vannucci et al., PRB 107, 195306 (2023). [6] T. K. Bracht et al., arXiv:2307.00304 (2023).

Keywords: quantum dots; quantum dot cavity systems; single photons; entangled photon pairs