Quantum key distribution with a single photon from a squeezed coherent state

Journal Article · Tue Apr 01 04:00:00 EST 2003 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.67.042307· OSTI ID:20633952

Matsuoka, Masahiro ^[1]; Hirano, Takuya ^[1]

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1. Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo (Japan)

Squeezing of the coherent state by optical parametric amplifier is shown to efficiently produce single-photon states with reduced multiphoton probabilities compared with the weak coherent light. It can be a better source for a longer-distance quantum key distribution and also for other quantum optical experiments. The necessary condition for a secure quantum key distribution given by Brassard et al. is analyzed as functions of the coherent-state amplitude and squeeze parameter. Similarly, the rate of the gained secure bits G after error correction and privacy amplification given by Luetkenhaus is calculated. Compared with the weak coherent light, it is found that G is about ten times larger and its high level continues on about two times longer distance. By improvement of the detector efficiency it is shown that the distance extends further. Measurement of the intensity correlation function and the relation to photon antibunching are discussed for the experimental verification of the single-photon generation.

• OSTI ID: 20633952
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 4 Vol. 67; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
AMPLIFICATION
AMPLITUDES
ANNIHILATION OPERATORS
CORRECTIONS
CORRELATION FUNCTIONS
CORRELATIONS
DISTANCE
DISTRIBUTION
EFFICIENCY
EIGENSTATES
ENERGY LEVELS
ERRORS
MULTI-PHOTON PROCESSES
OPTICS
PARAMETRIC AMPLIFIERS
PHOTONS
PROBABILITY
QUANTUM MECHANICS
SECRECY PROTECTION
VISIBLE RADIATION