Unambiguous coherent state identification: Searching a quantum database

Details Unambiguous coherent state identification: Searching a quantum database Unambiguous coherent state identification: Searching a quantum database

2007-06-13

arxiv.org/abs/0706.1892v2

Phys. Rev. A 76, 022326 (2007)

Physics

Quantum Physics

version accepted for publication, 12 pages, 3 figures

Scientific paper

10.1103/PhysRevA.76.022326

We consider an unambiguous identification of an unknown coherent state with one of two unknown coherent reference states. Specifically, we consider two modes of an electromagnetic field prepared in unknown coherent states alpha_1 and alpha_2, respectively. The third mode is prepared either in the state alpha_1 or in the state alpha_2. The task is to identify (unambiguously) which of the two modes are in the same state. We present a scheme consisting of three beamsplitters capable to perform this task. Although we don't prove the optimality, we show that the performance of the proposed setup is better than the generalization of the optimal measurement known for a finite-dimensional case. We show that a single beamsplitter is capable to perform an unambiguous quantum state comparison for coherent states optimally. Finally we propose an experimental setup consisting of 2N-1 beamsplitters for unambiguous identification among N unknown coherent states. This setup can be considered as a search in a quantum database. The elements of the database are unknown coherent states encoded in different modes of an electromagnetic field. The task is to specify the two modes that are excited in the same, though unknown, coherent state.

Affiliated with

Also associated with

No associations

Rating

Unambiguous coherent state identification: Searching a quantum database does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Unambiguous coherent state identification: Searching a quantum database, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Unambiguous coherent state identification: Searching a quantum database will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-450947