Optimal scheme for estimating a pure qubit state via local measurements
Quantum Physics
2009-11-07 v2
Abstract
We present the optimal scheme for estimating a pure qubit state by means of local measurements on N identical copies. We give explicit examples for low N. For large N, we show that the fidelity saturates the collective measurement bound up to order 1/N. When the signal state lays on a meridian of the Bloch sphere, we show that this can be achieved without classical communication.
Cite
@article{arxiv.quant-ph/0205026,
title = {Optimal scheme for estimating a pure qubit state via local measurements},
author = {E. Bagan and M. Baig and R. Munoz-Tapia},
journal= {arXiv preprint arXiv:quant-ph/0205026},
year = {2009}
}
Comments
Version to appear in PRL (minor changes, title changed)