English

A New Strategy of Quantum-State Estimation for Achieving the Cramer-Rao Bound

Quantum Physics 2013-05-29 v1

Abstract

We experimentally analyzed the statistical errors in quantum-state estimation and examined whether their lower bound, which is derived from the Cramer-Rao inequality, can be truly attained or not. In the experiments, polarization states of bi-photons produced via spontaneous parametric down-conversion were estimated employing tomographic measurements. Using a new estimation strategy based on Akaike's information criterion, we demonstrated that the errors actually approach the lower bound, while they fail to approach it using the conventional estimation strategy.

Keywords

Cite

@article{arxiv.quant-ph/0209074,
  title  = {A New Strategy of Quantum-State Estimation for Achieving the Cramer-Rao Bound},
  author = {Koji Usami and Yoshihiro Nambu and Yoshiyuki Tsuda and Keiji Matsumoto and Kazuo Nakamura},
  journal= {arXiv preprint arXiv:quant-ph/0209074},
  year   = {2013}
}

Comments

4 pages, 2 figures

R2 v1 2026-07-22T19:36:20.874Z