Experimental demonstration of free-space decoy-state quantum key distribution over 144 km.
We report on the experimental implementation of a Bennett-Brassard 1984 (BB84) protocol type quantum key distribution over a 144 km free-space link using weak coherent laser pulses. Optimization of the link transmission was achieved with bidirectional active telescope tracking, and the security was ensured by employing decoy-state analysis. This enabled us to distribute a secure key at a rate of 12.8 bit/s at an attenuation of about 35 dB. Utilizing a simple transmitter setup and an optical ground station capable of tracking a spacecraft in low earth orbit, this outdoor experiment demonstrates the feasibility of global key distribution via satellites.
Schmitt-Manderbach
Tobias
T
Max-Planck-Institute for Quantum Optics, D-85748 Garching, Germany. tschmitt@lmu.de
Weier
Henning
H
Fürst
Martin
M
Ursin
Rupert
R
Tiefenbacher
Felix
F
Scheidl
Thomas
T
Perdigues
Josep
J
Sodnik
Zoran
Z
Kurtsiefer
Christian
C
Rarity
John G
JG
Zeilinger
Anton
A
Weinfurter
Harald
H