We address high-precision measurements by active and passive interferometric schemes based on Gaussian states and operations. In particular, we look for the best states to be injected into their ports according to the quantum Cramér- Rao bound, i.e., maximizing the quantum Fisher information over all the involved parameters, given a constraint on the overall mean number of photons entering into the interferometer. We found that for passive interferometers involving only beam splitters, the optimal input leading to Heisenberg scaling is a pair of identical squeezed-coherent states with at most one-third of the total energy employed in squeezing. For active interferometers involving optical amplifiers, input coherent signals are enough to achieve Heisenberg scaling, given an optimal value of the amplification gain. For passive schemes our results clarify the role of squeezing in improving both the reference phase and the signal phase of an interferometer.
Bounds to precision for quantum interferometry with Gaussian states and operations / C. Sparaciari, S. Olivares, M.G.A. Paris. - In: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. B, OPTICAL PHYSICS. - ISSN 0740-3224. - 32:7(2015 Jul 01), pp. 1354-1359.
|Titolo:||Bounds to precision for quantum interferometry with Gaussian states and operations|
OLIVARES, STEFANO (Secondo)
PARIS, MATTEO (Ultimo)
|Parole Chiave:||phase measurement; mechanics; geometry; limit|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Progetto:||Quantum Probes for Complex Systems|
|Data di pubblicazione:||1-lug-2015|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1364/JOSAB.32.001354|
|Appare nelle tipologie:||01 - Articolo su periodico|