title: Enhanced resolution of lossy interferometry by coherent amplification of single photons.
abstract: In the quantum sensing context most of the efforts to design novel quantum techniques of sensing have been constrained to idealized, noise-free scenarios, in which effects of environmental disturbances could be neglected. In this work, we propose to exploit optical parametric amplification to boost interferometry sensitivity in the presence of losses in a minimally invasive scenario. By performing the amplification process on the microscopic probe after the interaction with the sample, we can beat the losses' detrimental effect on the phase measurement which affects the single-photon state after its interaction with the sample, and thus improve the achievable sensitivity.
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, piazzale Aldo Moro 5, I-00185 Roma, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Vitelli
authors.forename: Nicolò
authors.initials: N
authors.lastname: Spagnolo
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Toffoli
authors.forename: Fabio
authors.initials: F
authors.lastname: Sciarrino
authors.forename: Francesco
authors.initials: F
authors.lastname: De Martini