493 research outputs found
Space division multiplexing chip-to-chip quantum key distribution
Quantum cryptography is set to become a key technology for future secure
communications. However, to get maximum benefit in communication networks,
transmission links will need to be shared among several quantum keys for
several independent users. Such links will enable switching in quantum network
nodes of the quantum keys to their respective destinations. In this paper we
present an experimental demonstration of a photonic integrated silicon chip
quantum key distribution protocols based on space division multiplexing (SDM),
through multicore fiber technology. Parallel and independent quantum keys are
obtained, which are useful in crypto-systems and future quantum network
Characterization of the zero-dispersion wavelength variation in a strained highly nonlinear fiber
Theoretical and experimental investigation of a balanced phase-locked loop based clock recovery at a bit rate of 160 Gb/s
Experimental demonstration of the DPTS QKD protocol over a 170 km fiber link
Quantum key distribution (QKD) is a promising technology aiming at solving
the security problem arising from the advent of quantum computers. While the
main theoretical aspects are well developed today, limited performances, in
terms of achievable link distance and secret key rate, are preventing the
deployment of this technology on a large scale. More recent QKD protocols,
which use multiple degrees of freedom for the encoding of the quantum states,
allow an enhancement of the system performances. Here, we present the
experimental demonstration of the differential phase-time shifting protocol
(DPTS) up to 170 km of fiber link. We compare its performance with the
well-known coherent one-way (COW) and the differential phase shifting (DPS)
protocols, demonstrating a higher secret key rate up to 100 km. Moreover, we
propagate a classical signal in the same fiber, proving the compatibility of
quantum and classical light.Comment: 5 pages, 3 figures, journal pape
Information Reconciliation for High-Dimensional Quantum Key Distribution using Nonbinary LDPC codes
Information Reconciliation is an essential part of Quantum Key distribution
protocols that closely resembles Slepian-Wolf coding. The application of
nonbinary LDPC codes in the Information Reconciliation stage of a
high-dimensional discrete-variable Quantum Key Distribution setup is proposed.
We model the quantum channel using a -ary symmetric channel over which
qudits are sent. Node degree distributions optimized via density evolution for
the Quantum Key Distribution setting are presented, and we show that codes
constructed using these distributions allow for efficient reconciliation of
large-alphabet keys.Comment: 5 pages, 1 figure, submitted to International Symposium on Topics in
Codin
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