Phase variance of squeezed vacuum states

Details Phase variance of squeezed vacuum states Phase variance of squeezed vacuum states

2008-07-25

arxiv.org/abs/0807.4108v2

Phys. Rev. A 78, 043829 (2008)

Physics

Quantum Physics

Minor changes, version to appear in PRA, 8 pages, 2 figures

Scientific paper

10.1103/PhysRevA.78.043829

We consider the problem of estimating the phase of squeezed vacuum states within a Bayesian framework. We derive bounds on the average Holevo variance for an arbitrary number $N$ of uncorrelated copies. We find that it scales with the mean photon number, $n$, as dictated by the Heisenberg limit, i.e., as $n^{-2}$, only for $N>4$. For $N\leq 4$ this fundamental scaling breaks down and it becomes $n^{-N/2}$. Thus, a single squeezed vacuum state performs worse than a single coherent state with the same energy. We find the optimal splitting of a fixed given energy among various copies. We also compute the variance for repeated individual measurements (without classical communication or adaptivity) and find that the standard Heisenberg-limited scaling $n^{-2}$ is recovered for large samples.

Affiliated with

Also associated with

No associations

Rating

Phase variance of squeezed vacuum states 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 Phase variance of squeezed vacuum states, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase variance of squeezed vacuum states will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-325914