Related papers: Heisenberg-limited estimation robust to detector inefficiency in a multi-parameter Mach-Zehnder network with squeezed light

Heisenberg-limited estimation robust to detector inefficiency in a multi-parameter Mach-Zehnder network with squeezed light

URL: http://arxiv.org/abs/2104.02417v1
Date: Tue, 6 Apr 2021 10:46:29 GMT
Title: Heisenberg-limited estimation robust to detector inefficiency in a multi-parameter Mach-Zehnder network with squeezed light
Authors: Dario Gatto, Paolo Facchi and Vincenzo Tamma
Abstract summary: A simple and intuitive geometrical picture of the state evolution is provided by the Wigner functions of the state at each interferometer output channel. The protocol allows to detect the value of the sum $beta=frac12(varphi_2)+theta_mathrmin-theta_mathrmout$.
Score: 0.0
License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Abstract: We propose a multi-parameter quantum metrological protocol based on a Mach-Zehnder interferometer with a squeezed vacuum input state and an anti-squeezing operation at one of its output channels. A simple and intuitive geometrical picture of the state evolution is provided by the marginal Wigner functions of the state at each interferometer output channel. The protocol allows to detect the value of the sum $\beta=\frac{1}{2}(\varphi_1+\varphi_2)+\theta_\mathrm{in}-\theta_\mathrm{out}$, of the relative phase $\theta_\mathrm{in}-\theta_\mathrm{out}$ between the two squeezers, and the average of the phase delays $\varphi_1,\varphi_2$ in the two arms of the interferometer. The detection sensitivity scales at the Heisenberg limit and, remarkably, is robust to the detector inefficiency.

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