Stuttgart 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
SYPC: Symposium From Atoms to Photonic Circuits: Integrating Quantum Optics and Optical Communication
SYPC 3: From Atoms to Photonic Circuits: Integrating Quantum Optics and Optical Communication 3
SYPC 3.8: Vortrag
Freitag, 16. März 2012, 12:15–12:30, V47.02
Quantum key distribution using a single-photon emitting diode in the red spectral range — •Christian Kessler1, Fabian Hargart1, Markus Rau2, Martin Fuerst2, Wolfgang-Michael Schulz1, Marcus Eichfelder1, Robert Rossbach1, Sebastian Nauerth2, Michael Jetter1, Harald Weinfurter2,3, and Peter Michler1 — 1Institut für Halbleiteroptik und Funktionelle Grenzflächen, Universität Stuttgart, 70569 Stuttgart — 2Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 München — 3Max-Planck-Institut für Quantenoptik, 85748 Garching
In 1984 Bennett and Brassard presented a scheme for secure quantum key distribution (QKD), the so-called BB84 protocol. Several QKD-experiments have been arranged with strongly attenuated lasers. But due to multi-photon emission additional shrinking of the key compared to systems using single-photon sources (SPS) is necessary. Therefore, using a SPS afford higher key rates at the same total count rate.
In this report we present free-space quantum key distribution experiments using an electrically driven SPS, based on InP quantum dots. A polarizer in combination with an electro-optical modulator prepare the polarization state. After a free-space channel of about 50 cm the beam is detected and analyzed by a single-photon polarization analyzer setup. The influence of several excitation parameters, e.g. the peak-to-peak voltage, the DC voltage and the pulse width on the g(2)(0)-value and the transfer rate are investigated. Sifted key rates up to 81.6 kBits/s at a quantum bit error-rate of 4.2 % and a g(2)(0)-value of 0.48 were achieved.