title: Optimal architectures for long distance quantum communication.
abstract: Despite the tremendous progress of quantum cryptography, efficient quantum communication over long distances (≥ 1000 km) remains an outstanding challenge due to fiber attenuation and operation errors accumulated over the entire communication distance. Quantum repeaters (QRs), as a promising approach, can overcome both photon loss and operation errors, and hence significantly speedup the communication rate. Depending on the methods used to correct loss and operation errors, all the proposed QR schemes can be classified into three categories (generations). Here we present the first systematic comparison of three generations of quantum repeaters by evaluating the cost of both temporal and physical resources, and identify the optimized quantum repeater architecture for a given set of experimental parameters for use in quantum key distribution. Our work provides a roadmap for the experimental realizations of highly efficient quantum networks over transcontinental distances.
authors.affiliation: Department of Electrical Engineering, Yale University, New Haven, CT 06511 USA.
authors.forename: Sreraman
authors.initials: S
authors.lastname: Muralidharan
authors.affiliation: Department of Applied Physics, Yale University, New Haven, CT 06511 USA.
authors.forename: Linshu
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708 USA.
authors.forename: Jungsang
authors.initials: J
authors.lastname: Kim
authors.affiliation: Institute of Quantum computing, University of Waterloo, N2L 3G1 Waterloo, Canada.
authors.forename: Norbert
authors.initials: N
authors.lastname: Lütkenhaus
authors.affiliation: Department of Physics, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Mikhail D
authors.initials: MD
authors.lastname: Lukin
authors.affiliation: Department of Applied Physics, Yale University, New Haven, CT 06511 USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Jiang