In- and out-of-equilibrium quantum metrology with mean-field quantum criticality
| Autor: | Sascha Wald, Fernando L. Semião, Saulo V. Moreira |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Phase transition Quantum Physics Toy model Statistical Mechanics (cond-mat.stat-mech) FOS: Physical sciences 01 natural sciences 010305 fluids & plasmas symbols.namesake Criticality Critical point (thermodynamics) 0103 physical sciences Quantum metrology symbols Dissipative system Statistical physics 010306 general physics Fisher information Quantum Physics (quant-ph) Quantum Condensed Matter - Statistical Mechanics |
| Zdroj: | Physical review. E. 101(5-1) |
| ISSN: | 2470-0053 |
| Popis: | We study the influence that collective transition phenomena have on quantum metrological protocols. The single spherical quantum spin (SQS) serves as stereotypical toy model that allows analytical insights on a mean-field level. First, we focus on equilibrium quantum criticality in the SQS and obtain the quantum Fisher information analytically, which is associated with the minimum lower bound for the precision of estimation of the parameter driving the phase transition. We compare it with the Fisher information for a specific experimental scenario where photoncounting-like measurements are employed. We find how quantum criticality and squeezing are useful resources in the metrological scenario. Second, we obtain the quantum Fisher information for the out of equilibrium transition in the dissipative non-equilibrium steady state (NESS), and investigate how the presence of dissipation affects the parameter estimation. In this scenario, it is known that the critical point is shifted by an amount which depends on the dissipation rate. This is used here to design high precision protocols for a whole range of the transition-driving parameter in the ordered phase. In fact, for certain values of the parameter being estimated, dissipation may be used to obtain higher precision when compared to the equilibrium scenario. Comment: 9 pages, 5 figures. Revised version, to appear in PRE |
| Databáze: | OpenAIRE |
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