English

Quantum metrology at level anti-crossing

Quantum Physics 2018-01-24 v1

Abstract

We address parameter estimation in two-level systems exhibiting level anti-crossing and prove that universally optimal strategies for parameter estimation may be designed, that is, we may find a parameter independent measurement scheme leading to the ultimate quantum precision independently on the nature and the value of the parameter of interest. Optimal estimation may be achievable also at high temperature depending on the structure of the two-level Hamiltonian. Finally, we show that no improvement is achievable by dynamical strategies and discuss examples of applications.

Keywords

Cite

@article{arxiv.1710.03200,
  title  = {Quantum metrology at level anti-crossing},
  author = {Luca Ghirardi and Ilaria Siloi and Paolo Bordone and Filippo Troiani and Matteo G. A. Paris},
  journal= {arXiv preprint arXiv:1710.03200},
  year   = {2018}
}
R2 v1 2026-06-22T22:07:50.952Z