Quantum metrology of spatial deformation using arrays of classical and quantum light emitters

Abstract

We introduce spatial deformations to an array of light sources and study how the estimation precision of the interspacing distance d changes with the sources of light used. The quantum Fisher information (QFI) is used as the figure of merit in this work to quantify the amount of information we have on the estimation parameter. We derive the generator of translationsĜ in d due to an arbitrary homogeneous deformation applied to the array. We show how the variance of the generator can be used to easily consider how different deformations and light sources can effect the estimation precision. The single-parameter estimation problem is applied to the array, and we report on the optimal state that maximizes the QFI for d. Contrary to what may have been expected, the higher average mode occupancies of the classical states performs better in estimating d when compared with single photon emitters (SPEs). The optimal entangled state is constructed from the eigenvectors of the generator and found to outperform all these states. We also find the existence of multiple optimal estimators for the measurement of d. Our results find applications in evaluating stresses and strains, fracture prevention in materials expressing great sensitivities to deformations, and selecting frequency distinguished quantum sources from an array of reference sources.

Intrinsic Sensitivity Limits for Multiparameter Quantum Metrology

“…𝑔 𝑗 𝑘 𝑑𝜃 𝑗 𝑑𝜃 𝑘 (10) and computing 𝑑𝑈 = −𝑖𝑈 𝑗 𝐻 𝑗 𝑑𝜃 𝑗 , we find that the metric explicitly depends on the generators from Eq. ( 7) through…”

“…However, much less is known about the corresponding bounds for the simultaneous estimation of multiple parameters. Multiparameter quantum metrology finds many important applications in fields as diverse as imaging [4][5][6], field sensing [7][8][9], sensor networks [10][11][12], and remote sensing [13] to cite but a few examples. In this case, the QCRB is a matrix inequality and the ultimate bound is generally not saturable for all parameters.…”

Forbidden Radiation Angles of Quantum Antennas

“…Research on quantum antennae has important applied signifi cance. These systems can act as sources in new areas such as quantum microscopy [6,7], quantum sensing [8], quantum communication [9], and quantum optical computers [10].…”

Optimal Imaging of Remote Bodies Using Quantum Detectors

“…Recently, Tsang et al showed that the far field quantum state of light retains a significant amount of information about the separation of two identical incoherent point sources, even when their angular separation approaches zero [12]. Moreover, this information can be extracted with a suitable measurement [13], for example using spatial-mode demultiplexing [14]. Recently, a series of experiments demonstrated sub-Rayleigh resolution for two incoherent point sources, using image inversion interferometry [15,16], digital holography [17], and TEM 01 heterodyne detection [18].…”