Robust excitation of C-band quantum dots for quantum communication


The Walther Group published a new paper in Applied Physics Letters

Building a quantum internet requires efficient and reliable quantum hardware, from photonic sources to quantum repeaters and detectors, ideally operating at telecommunication wavelengths. Thanks to their high brightness and single-photon purity, quantum dot (QD) sources hold the promise to achieve high communication rates for quantum-secured network applications. Furthermore, it was recently shown that excitation schemes such as longitudinal acoustic phonon-assisted (LA) pumping provide security benefits by scrambling the coherence between the emitted photon-number states. In this work, we investigate further advantages of LA-pumped quantum dots with emission in the telecom C-band as a core hardware component of the quantum internet. We experimentally demonstrate how varying the pump power and spectral detuning with respect to the excitonic transition can improve quantum-secured communication rates and provide stable emission statistics regardless of network-environment fluctuations. These findings have significant implications for general implementations of QD single-photon sources in practical quantum communication networks.

  • M. Vyvlecka, L. Jehle, C. Nawrath, F. Giorgino, M. Bozzio, R. Sittig, M. Jetter, S. L. Portalupi, P. Michler, P. Walther
    Robust excitation of C-band quantum dots for quantum communication
    Applied Physics Letters 123 (2023).