Quantum metrology with nonequilibrium steady states of quantum spin chains
Abstract
We consider parameter estimations with probes being the boundarydriven or dissipated nonequilibrium steady states of X X Z spin1 /2 chains. The parameters to be estimated are the dissipation coupling and the anisotropy of the spinspin interaction. In the weakcoupling regime we compute the scaling of the Fisher information, i.e., the inverse best sensitivity among all estimators, with the number of spins. We find superlinear scalings and transitions between the distinct isotropic and anisotropic phases. We also look at the best relative error, which decreases with the number of particles faster than the shotnoise only for the estimation of anisotropy.
 Publication:

Physical Review A
 Pub Date:
 December 2014
 DOI:
 10.1103/PhysRevA.90.062130
 arXiv:
 arXiv:1412.1977
 Bibcode:
 2014PhRvA..90f2130M
 Keywords:

 06.20.Dk;
 75.10.Pq;
 03.65.Yz;
 03.67.Ac;
 Measurement and error theory;
 Spin chain models;
 Decoherence;
 open systems;
 quantum statistical methods;
 Quantum algorithms protocols and simulations;
 Quantum Physics;
 Condensed Matter  Strongly Correlated Electrons;
 Nonlinear Sciences  Exactly Solvable and Integrable Systems;
 Statistics  Applications
 EPrint:
 12 pages, 10 figures