Premium
Optimum Discrimination of Non‐orthogonal Quantum States: An Optical Realization
Author(s) -
Bergou János A.,
Hillery Mark,
Sun Yuqing
Publication year - 2001
Publication title -
fortschritte der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.469
H-Index - 71
eISSN - 1521-3978
pISSN - 0015-8208
DOI - 10.1002/1521-3978(200110)49:10/11<915::aid-prop915>3.0.co;2-r
Subject(s) - a priori and a posteriori , realization (probability) , quantum entanglement , observable , von neumann architecture , quantum state , quantum , set (abstract data type) , state (computer science) , computer science , photon , statistical physics , quantum mechanics , mathematics , topology (electrical circuits) , physics , algorithm , statistics , philosophy , epistemology , combinatorics , programming language , operating system
Since the state of a quantum system is not an observable, it cannot be determined completely, in principle, if no a priori information is available. In this case, one needs to resort to various estimation strategies. The situation is completely different if a priori knowledge is available. Even unambigous discrimination is possible if the system is always prepared in a state that is selected from a known set of quantum states that are not orthogonal but linearly independent. This type of discrimination strategy has a higher probability of success by using generalised measurements than by using standard von Neumann measurements. We discuss here possible optical realizations, via generalized interferometers and single photon states, for the implementation of strategies that maximize the success rate. The implementations are based on exact analytical results. We also discuss possible applications for entanglement enhancement and quantum communication protocols.