title: Experimental demonstration of free-space decoy-state quantum key distribution over 144 km.
abstract: 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.
authors.affiliation: Max-Planck-Institute for Quantum Optics, D-85748 Garching, Germany. tschmitt@lmu.de
authors.forename: Tobias
authors.initials: T
authors.lastname: Schmitt-Manderbach
authors.forename: Henning
authors.initials: H
authors.lastname: Weier
authors.forename: Martin
authors.initials: M
authors.lastname: Fürst
authors.forename: Rupert
authors.initials: R
authors.lastname: Ursin
authors.forename: Felix
authors.initials: F
authors.lastname: Tiefenbacher
authors.forename: Thomas
authors.initials: T
authors.lastname: Scheidl
authors.forename: Josep
authors.initials: J
authors.lastname: Perdigues
authors.forename: Zoran
authors.initials: Z
authors.lastname: Sodnik
authors.forename: Christian
authors.initials: C
authors.lastname: Kurtsiefer
authors.forename: John G
authors.initials: JG
authors.lastname: Rarity
authors.forename: Anton
authors.initials: A
authors.lastname: Zeilinger
authors.forename: Harald
authors.initials: H
authors.lastname: Weinfurter