2011/08/06 by Osamu Hirotaand, Hirota, Osamu, Kentaro Kato +3
Physics and Astronomy · #FOS: Physical sciences #Quantum Mechanics and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.1108.1517
openalex publication_date 2011/08/06 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
This Letter verifies the potential of several classes of entangled coherent state in well known quantum metrology which includes detection of classical external force, and shows that there is a class of entangled coherent state for the external force detection system without the quantum limit in the detection of the light. In the case of the precision measurement of continuos parameter like phase measurement, the entangled coherent state with perfect entanglement does not provide remarkable benefit, but we provide a concrete example that certain class of entangled coherent state gives a remarkable sensitive detection scheme in the discrimination of digital signal affected by external force.