2006/08/28 by J. Niset, Antonio Acín, A. Acin +10
Computer Science · Physics and Astronomy · #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum optics and atomic interactions #quant-ph
paper · pdf · doi:10.1103/physrevlett.98.260404
published as Phys. Rev. Lett. 98, 260404 (2007) · 4 pages, 2 figures
arxiv created 2006/08/28 · openalex publication_date 2007/06/26 · arxiv updated 2013/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It is shown that the ensemble P(alpha),|alpha|alpha;*, where P(alpha) is a Gaussian distribution of finite variance and |alpha is a coherent state, can be better discriminated with an entangled measurement than with any local strategy supplemented by classical communication. Although this ensemble consists of products of quasiclassical states without any squeezing, it thus exhibits a purely quantum feature. This remarkable effect is demonstrated experimentally by implementing the optimal local strategy on coherent states of light together with a global strategy that yields a higher fidelity.