Superiority of entangled measurements over all local strategies for the estimation of product coherent states

Niset J., Acin A., Andersen U. L., Cerf N. J., Garcia-Patron R., Navascues M., ...Daha Fazla

PHYSICAL REVIEW LETTERS, cilt.98, sa.26, 2007 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 98 Sayı: 26
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1103/physrevlett.98.260404
  • Dergi Adı: PHYSICAL REVIEW LETTERS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Dokuz Eylül Üniversitesi Adresli: Hayır

Özet

It is shown that the ensemble {P(alpha),vertical bar alpha >vertical bar 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.