We report on in-lab free space quantum key distribution (QKD) experiments over 40 cm distance using highly efficient electrically driven quantum dot single-photon sources emitting in the red as well as near-infrared spectral range. In the case of infrared emitting devices, we achieve sifted key rates of 27.2 kbit s −1 (35.4 kbit s −1) at a quantum bit error rate (QBER) of 3.9% (3.8%) and a g (2)(0) value of 0.35 (0.49) at moderate (high) excitation. The red emitting diodes generate sifted keys at a rate of 95.0 kbit s −1 at a QBER of 4.1% and a g (2)(0) value of 0.49. This first successful proof of principle QKD experiment based on electrically operated semiconductor single-photon sources can be considered as a major step toward practical and efficient quantum cryptography scenarios.
Publication: Quantum key distribution using quantum dot single-photon emitting diodes in the red and near infrared spectral range
Tobias Heindel, Christian A Kessler, Markus Rau, Christian Schneider, Martin Fürst, Fabian Hargart, Wolfgang-Michael Schulz, Marcus Eichfelder, Robert Roßbach, Sebastian Nauerth, Matthias Lermer, Henning Weier, Michael Jetter, Martin Kamp, Stephan Reitzenstein, Sven Höfling, Peter Michler, Harald Weinfurter and Alfred Forchel 
New J. Phys. 14, 083001 (2012)
Contact person: Prof. Peter Michler