Regensburg 2022 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 19: Materials and Devices for Quantum Technology 1
HL 19.1: Invited Talk
Wednesday, September 7, 2022, 09:30–10:00, H34
Quantum Interference of Identical Photons from Remote GaAs Quantum Dots — •Giang Nam Nguyen1, Liang Zhai1, Clemens Spinnler1, Julian Ritzmann2, Mattias C. Löbl1, Andreas D. Wieck2, Arne Ludwig2, Alisa Javadi1, and Richard J. Warburton1 — 1Department of Physics, University of Basel — 2Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum
Efficient generation and detection of coherent single photons are key to advances in photonic quantum technologies such as quantum computation, quantum simulation, and quantum communication. For applications, a significant roadblock is the poor quantum coherence upon interfering single photons created by independent emitters.
Here, we present near-unity two-photon interference visibilities from two separate GaAs quantum dots [1]. This high visibility (~93%) is achieved under rigorous conditions: there is no Purcell enhancement, no temporal post-selection, no narrow spectral-filtering, nor frequency stabilization. Using photons emitted from two remote quantum dots, we demonstrate a photonic CNOT gate. Interfering photons in this quantum logic gate, we generate an entangled two-photon state using photons from separate semiconductor chips. We obtain an entanglement fidelity of (85 +- 1)%, exceeding the CHSH threshold for violating Bell inequalities. This result highlights the importance of the high two-photon visibility for high fidelity entanglement operations.
[1] L. Zhai et al., Nature Nanotechnol. (2022)