Practical purification scheme for decohered coherent-state superpositions via partial homodyne detection

Journal Article · Sat Apr 15 00:00:00 EDT 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.73.0· OSTI ID:20787077

Suzuki, Shigenari ^[1]; Takeoka, Masahiro; Sasaki, Masahide ^[1]; Andersen, Ulrik L ^[2]; Kannari, Fumihiko ^[3]

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1. Quantum Information Technology Group, National Institute of Information and Communications Technology (NICT), 4-2-1 Nukui-kitamachi, Koganei, Tokyo 184-8795 (Japan)
2. Institut fuer Optik, Information und Photonik, Max-Planck Forschungsgruppe, Universitaet Erlangen-Nuernberg, Guenther-Scharowsky str. 1, 91058, Erlangen (Germany)
3. Department of Electronics and Electrical Engineering, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522 (Japan)

We present a simple protocol to purify a coherent-state superposition that has undergone a linear lossy channel. The scheme constitutes only a single beam splitter and a homodyne detector, and thus is experimentally feasible. In practice, a superposition of coherent states is transformed into a classical mixture of coherent states by linear loss, which is usually the dominant decoherence mechanism in optical systems. We also address the possibility of producing a larger amplitude superposition state from decohered states, and show that in most cases the decoherence of the states are amplified along with the amplitude.

• OSTI ID: 20787077
• Journal Information: Physical Review. A, Vol. 73, Issue 4; Other Information: DOI: 10.1103/PhysRevA.73.042304; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
AMPLITUDES
ANNIHILATION OPERATORS
BEAM SPLITTING
DATA TRANSMISSION
DETECTION
EIGENSTATES
ENERGY LEVELS
INFORMATION THEORY
MIXTURES
OPTICAL SYSTEMS
OPTICS
QUANTUM MECHANICS