Freiburg 2019 – wissenschaftliches Programm
FM 31.5: Talk
Dienstag, 24. September 2019, 15:15–15:30, 1009
Performance Optimization and Security Monitoring for Single-Photon QKD — •Timm Kupko, Lucas Rickert, Martin v. Helversen, Stephan Reitzenstein, and Tobias Heindel — Institut für Festkörperphysik, Technische Universität Berlin, 10623 Berlin, Germany
Solid-state single-photon sources (SPSs) have the potential to boost the performance of quantum-key-distribution (QKD) systems [1,2]. To fully exploit realistic sub-poissonian light sources for applications in quantum communication, however, a detailed analysis and optimization of the receiver side is necessary.
Here, we analyze the effect of temporal filtering on the performance of QKD systems implemented with realistic quantum-light sources. For this purpose, we developed a basic QKD testbed comprising a deterministically fabricated QD-based SPS and a receiver module designed for four-state polarization coding. We analyze the sifted key fraction, the quantum bit error ratio, and g(2)(0) expected in full implementations of the BB84 protocol under variation of the acceptance time-window. This routine enables us to choose optimal filter settings depending on the losses of the quantum channel. Furthermore, we demonstrate real-time security monitoring by evaluating g(2)(0) inside the quantum channel during key distillation. The presented approach can be adapted and extended for most other applications in quantum communication employing realistic quantum light sources.
 E. Waks et al., Phys. Rev. A 66, 042315 (2002)
 T. Heindel et al., New J. Phys. 14, 083001 (2012)