Feedback in the problem of distinguishing between two nonorthogonal coherent states

Journal Article · Tue Feb 15 00:00:00 EST 2011 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S106377611006110X· OSTI ID:22028162

Chekhova, M V ^[1]

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1. Moscow State University (Russian Federation)

Feedback is proposed for distinguishing between two weak coherent states with phases differing by {approx}{pi}. The mutual nonorthogonality of such states gives rise to a discrimination error, which can be reduced by using feedback. An optical quantum channel is discussed where the input is classical information encoded in two weak coherent states. For a channel with feedback, the discrimination error probability is calculated, and the mutual entropy that quantifies the fidelity between input and output is evaluated. We find that the use of a feedback loop in a quantum communication channel can increase the mutual entropy when canonical position or photon number is measured.

• OSTI ID: 22028162
• Journal Information: Journal of Experimental and Theoretical Physics, Vol. 112, Issue 2; Other Information: Copyright (c) 2011 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DATA TRANSMISSION
EIGENSTATES
ENTROPY
ERRORS
FEEDBACK
PHOTONS
PROBABILITY
QUANTUM INFORMATION
QUANTUM NUMBERS
QUANTUM STATES