Strathprints Home | Open Access | Browse | Search | User area | Copyright | Help | Library Home | SUPrimo

Unambiguous comparison of the states of multiple quantum systems

Chefles, A. and Andersson, E. and Jex, I. (2004) Unambiguous comparison of the states of multiple quantum systems. Journal of Physics A: Mathematical and Theoretical, 37 (29). pp. 7315-7340. ISSN 0305-4470

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

We consider N quantum systems initially prepared in pure states and address the problem of unambiguously comparing them. One may ask whether or not all N systems are in the same state. Alternatively, one may ask whether or not the states of all N systems are different. We investigate the possibility of unambiguously obtaining this kind of information. It is found that some unambiguous comparison tasks are possible only when certain linear independence conditions are satisfied. We also obtain measurement strategies for certain comparison tasks which are optimal under a broad range of circumstances, in particular when the states are completely unknown. Such strategies, which we call universal comparison strategies, are found to have intriguing connections with the problem of quantifying the distinguishability of a set of quantum states and also with unresolved conjectures in linear algebra. We finally investigate a potential generalization of unambiguous state comparison, which we term unambiguous overlap filtering.

Item type: Article
ID code: 6192
Keywords: quantum, quantum systems, measurement strategies, linear algebra, quantum states, Physics
Subjects: Science > Physics
Department: Unknown Department
Faculty of Science > Physics
Related URLs:
Depositing user: Miss Darcy Spiller
Date Deposited: 02 Jun 2008
Last modified: 16 Jul 2013 20:03
URI: http://strathprints.strath.ac.uk/id/eprint/6192

Actions (login required)

View Item