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Related papers: Phase estimation with photon number constraint

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We investigate the ability of a quantum measurement device to discriminate two states or, generically, two hypothesis. In full generality, the measurement can be performed a number $n$ of times, and arbitrary pre-processing of the states…

Quantum Physics · Physics 2017-04-26 Christoph Hirche , Masahito Hayashi , Emilio Bagan , John Calsamiglia

The quantum Fisher information constrains the achievable precision in parameter estimation via the quantum Cram\'er-Rao bound, which has attracted much attention in Hermitian systems since the 60s of the last century. However, less…

Quantum Physics · Physics 2021-03-15 Jianning Li , Haodi Liu , Zhihai Wang , Xuexi Yi

Quantum state estimation aims at determining the quantum state from observed data. Estimating the full state can require considerable efforts, but one is often only interested in a few properties of the state, such as the fidelity with a…

Quantum Physics · Physics 2016-12-15 Xikun Li , Jiangwei Shang , Hui Khoon Ng , Berthold-Georg Englert

The quantum fisher information and quantum correlation parameters are employed to study the application of non-classical light to the problem of parameter estimation. It is shown that the optimal measurement sensitivity of a quantum state…

Quantum Physics · Physics 2015-01-09 Jaspreet Sahota , Nicolás Quesada

In probabilistic quantum metrology, one aims at finding weak measurements that concentrate the Fisher Information on the resulting quantum states, post-selected according to the weak outcomes. Though the Quantum Cram\'er-Rao bound itself…

Quantum Physics · Physics 2022-07-08 Massimo Frigerio , Stefano Olivares , Matteo G. A. Paris

We present the first experimental demonstration of the maximum confidence measurement strategy for quantum state discrimination. Applying this strategy to an arbitrary set of states assigns to each input state a measurement outcome which,…

Quantum Physics · Physics 2009-11-13 Peter J. Mosley , Sarah Croke , Ian A. Walmsley , Stephen M. Barnett

We experimentally demonstrate a general criterion to identify entangled states useful for the estimation of an unknown phase shift with a sensitivity higher than the shot-noise limit. We show how to exploit this entanglement on the examples…

We study informationally overcomplete measurements for quantum state estimation so as to clarify their tomographic significance as compared with minimal informationally complete measurements. We show that informationally overcomplete…

Quantum Physics · Physics 2014-08-06 Huangjun Zhu

Precision measurements with quantum systems rely on our ability to trace the differences between experimental signals to variations in unknown physical parameters. In this Letter we derive the Fisher information and the ensuing Cramer-Rao…

Quantum Physics · Physics 2015-06-17 Søren Gammelmark , Klaus Mølmer

Phase measurement using a lossless Mach-Zehnder interferometer with certain entangled $N$-photon states can lead to a phase sensitivity of the order of 1/N, the Heisenberg limit. However, previously considered output measurement schemes are…

Quantum Physics · Physics 2009-11-13 Yang Gao , Hwang Lee

Quantum Fisher Information (QFI) is a measure quantifying the sensitivity of a quantum state with respect to changes in tuning parameters in quantum metrology, and defining quantum speed limits. We show that even if the quantum state is…

Quantum Physics · Physics 2025-07-23 Alexander Kruchkov

The Kennedy-like receiver is a quasi-optimal receiver employed in binary phase-shift-keyed communication schemes with coherent states. It is based on the interference of the two signals encoding the message with a reference local oscillator…

Quantum Physics · Physics 2016-11-15 Matteo Bina , Alessia Allevi , Maria Bondani , Stefano Olivares

In this letter, we show that for all the so-called path-symmetric states, the measurement of parity of photon number at the output of an optical interferometer achieves maximal phase sensitivity at the quantum Cramer-Rao bound. Such optimal…

Quantum Physics · Physics 2015-08-25 Sejong Kim , Kaushik P. Seshadreesan , Jonathan P. Dowling , Hwang Lee

Optical phase estimation is a vital measurement primitive that is used to perform accurate measurements of various physical quantities like length, velocity and displacements. The precision of such measurements can be largely enhanced by…

A simple derivation of the optimal state estimation of a quantum bit was obtained by using the no-signaling principle. In particular, the no-signaling principle determines a unique form of the guessing probability independently of figures…

Quantum Physics · Physics 2015-05-20 Yeong-Deok Han , Joonwoo Bae , Xiang-Bin Wang , Won-Young Hwang

In this paper, we propose a nonlinear interferometer with feedback loops and explore its efficiency for phase estimation. We analyse two feedback schemes, one where both modes of the interferometer are fed-back into the device and another…

Quantum Physics · Physics 2025-07-24 Shivani Singh , Craig S. Hamilton , Igor Jex

We provide a bound on the minimum error when discriminating among quantum states, using the no-signaling principle. The bound is general in that it depends on neither dimensions nor specific structures of given quantum states to be…

Quantum Physics · Physics 2010-09-23 Won-Young Hwang , Joonwoo Bae

As one of the main pillars of quantum technologies, quantum metrology aims to improve measurement precision using techniques from quantum information. The two main strategies to achieve this are the preparation of nonclassical states and…

Quantum Physics · Physics 2025-09-16 Matteo Fadel , Noah Roux , Manuel Gessner

Optical noon states (|N,0> + |0,N>) are an important resource for Heisenberg-limited metrology and quantum lithography. The only known methods for creating noon states with arbitrary $N$ via linear optics and projective measurments seem to…

Quantum Physics · Physics 2007-05-23 Pieter Kok

Quantum metrology exploits quantum correlations to make precise measurements with limited particle numbers. By utilizing inter- and intra- mode correlations in an optical interferometer, we find a state that combines entanglement and…

Quantum Physics · Physics 2016-04-21 P. A. Knott , T. J. Proctor , A. J. Hayes , J. P. Cooling , J. A. Dunningham