TY - JOUR
T1 - Feasibility of 300 km quantum key distribution with entangled states
AU - Scheidl, T.
AU - Ursin, R.
AU - Fedrizzi, A.
AU - Ramelow, S.
AU - Ma, X.-S.
AU - Herbst, T.
AU - Prevedel, R.
AU - Ratschbacher, L.
AU - Kofler, J.
AU - Jennewein, T.
AU - Zeillinger, A.
PY - 2009
Y1 - 2009
N2 - A significant limitation of practical quantum key distribution (QKD) setups is currently their limited operational range. It has recently been emphasized (Ma et al 2007 Phys. Rev. A 76 012307) that entanglementbased QKD systems can tolerate higher channel losses than systems based on weak coherent laser pulses (WCP), in particular, when the source is located symmetrically between the two communicating parties, Alice and Bob. In the work presented here, we experimentally study this important advantage by implementing different entanglement-based QKD setups on a 144 km free-space link between the two Canary Islands of La Palma and Tenerife. We established three different configurations where the entangled photon source was placed at Alice's location, asymmetrically between Alice and Bob and symmetrically in the middle between Alice and Bob, respectively. The resulting quantum channel attenuations of 35, 58 and 71 dB, respectively, significantly exceed the limit for WCP systems (Ma et al 2007 Phys. Rev. A 76 012307). This confirms that QKD over distances of 300 km and even more is feasible with entangled state sources placed in the middle between Alice and Bob. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
AB - A significant limitation of practical quantum key distribution (QKD) setups is currently their limited operational range. It has recently been emphasized (Ma et al 2007 Phys. Rev. A 76 012307) that entanglementbased QKD systems can tolerate higher channel losses than systems based on weak coherent laser pulses (WCP), in particular, when the source is located symmetrically between the two communicating parties, Alice and Bob. In the work presented here, we experimentally study this important advantage by implementing different entanglement-based QKD setups on a 144 km free-space link between the two Canary Islands of La Palma and Tenerife. We established three different configurations where the entangled photon source was placed at Alice's location, asymmetrically between Alice and Bob and symmetrically in the middle between Alice and Bob, respectively. The resulting quantum channel attenuations of 35, 58 and 71 dB, respectively, significantly exceed the limit for WCP systems (Ma et al 2007 Phys. Rev. A 76 012307). This confirms that QKD over distances of 300 km and even more is feasible with entangled state sources placed in the middle between Alice and Bob. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
U2 - 10.1088/1367-2630/11/8/085002
DO - 10.1088/1367-2630/11/8/085002
M3 - Artikel
VL - 11
JO - New Journal of Physics
JF - New Journal of Physics
ER -