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Related papers: Quantum metrology with entangled coherent states

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In this paper we present a search algorithm that finds useful optical quantum states which can be created with current technology. We apply the algorithm to the field of quantum metrology with the goal of finding states that can measure a…

Quantum Physics · Physics 2016-08-03 P. A. Knott

We develop an original approach for the quantitative characterisation of the entanglement properties of, possibly mixed, bi- and multipartite quantum states of arbitrary finite dimension. Particular emphasis is given to the derivation of…

Quantum Physics · Physics 2009-11-11 Florian Mintert , Andre R. R. Carvalho , Marek Kus , Andreas Buchleitner

We propose a method to prepare entangled states and implement quantum computation with atoms in optical cavities. The internal state of the atoms are entangled by a measurement of the phase of light transmitted through the cavity. By…

Quantum Physics · Physics 2009-11-10 Anders S. Sorensen , Klaus Molmer

We study the precise phase estimation using squeezed states with photon losses present. Our exact quantum Fisher information calculation shows significant quantum enhancement and thus reveals the benchmark for practical quantum metrology in…

Quantum Physics · Physics 2013-08-13 Xiao-Xiao Zhang , Yu-Xiang Yang , Xiang-Bin Wang

When standard light sources are employed, the precision of the phase determination is limited by the shot noise. Quantum entanglement provides means to exceed this limit with the celebrated example of N00N states that saturate the ultimate…

Quantum Physics · Physics 2010-06-01 M. Kacprowicz , R. Demkowicz-Dobrzanski , W. Wasilewski , K. Banaszek , I. A. Walmsley

An extension to computational mechanics complexity measure is proposed in order to tackle quantum states complexity quantification. The method is applicable to any $n-$partite state of qudits through some simple modifications. A Werner…

Computational Physics · Physics 2011-10-28 Yuri Campbell , José Roberto Castilho Piqueira

Distributed quantum metrology can enhance the sensitivity for sensing spatially distributed parameters beyond the classical limits. Here we demonstrate distributed quantum phase estimation with discrete variables to achieve Heisenberg limit…

In the realm of quantum information processing, the efficient characterization of entangled states poses an overwhelming challenge, rendering the traditional methods including quantum tomography unfeasible and impractical. To tackle this…

Quantum Physics · Physics 2025-12-09 Ye-Chao Liu , Jiangwei Shang

The problem of the estimation of multiple phases (or of commuting unitaries) is considered. This is a sub-model of the estimation of a completely unknown unitary operation where it has been shown in recent works that there are considerable…

Quantum Physics · Physics 2007-05-23 Manuel A. Ballester

There has been much interest in developing phase estimation schemes which beat the so-called Heisenberg limit, i.e., for which the phase resolution scales better than 1/n, where n is a measure of resources such as the average photon number…

Quantum Physics · Physics 2013-07-11 Michael J. W. Hall

In this paper, we are interested in detecting the presence of a nearby phase-sensitive object, where traveling light works out under a low-photon loss rate. Here we investigate the optimal quantum phase estimation with generalized…

Quantum Physics · Physics 2020-07-30 Seung-Woo Lee , Su-Yong Lee , Jaewan Kim

Quantum states featuring extensive multipartite entanglement are a resource for quantum-enhanced metrology, with sensitivity up to the Heisenberg limit. However, robust generation of these states using unitary dynamics typically requires…

This paper presents simulations of the state vector dynamics for a pair of atomic samples which are being probed by phase shift measurements on an optical beam passing through both samples. We show how measurements, which are sensitive to…

Quantum Physics · Physics 2016-09-08 Antonio Di Lisi , Klaus Moelmer

Studies of quantum metrology have shown that the use of many-body entangled states can lead to an enhancement in sensitivity when compared to product states. In this paper, we quantify the metrological advantage of entanglement in a setting…

In optical interferometry multi-mode entanglement is often assumed to be the driving force behind quantum enhanced measurements. Recent work has shown this assumption to be false: single mode quantum states perform just as well as their…

Quantum Physics · Physics 2015-04-15 P. A. Knott , T. J. Proctor , Kae Nemoto , J. A. Dunningham , W. J. Munro

Bipartite entangled quantum states with a positive partial transpose (PPT), i.e., PPT entangled states, are usually considered very weakly entangled. Since no pure entanglement can be distilled from them, they are also called bound…

Quantum Physics · Physics 2021-08-26 Károly F. Pál , Géza Tóth , Erika Bene , Tamás Vértesi

Entangled coherent states are useful for various applications in quantum information processing but they are are sensitive to loss. We propose a scheme to generate distributed entangled coherent states over a lossy environment in such a way…

Quantum Physics · Physics 2015-06-17 A. P. Lund , T. C. Ralph , H. Jeong

Precision metrology and quantum measurement often demand matter be prepared in well defined quantum states for both internal and external degrees of freedom. Laser-cooled neutral atoms localized in a deeply confining optical potential…

Quantum Physics · Physics 2009-11-13 Jun Ye , H. J. Kimble , Hidetoshi Katori

Quantum parameter estimation is central to many fields such as quantum computation, communications and metrology. Optimal estimation theory has been instrumental in achieving the best accuracy in quantum parameter estimation, which is…

Quantum Physics · Physics 2015-06-18 Shibdas Roy , Ian R. Petersen , Elanor H. Huntington

We investigate phase estimation in a lossy interferometer using entangled coherent states, with particular focus on a scenario where no reference beam is employed. By calculating the quantum Fisher information, we reveal two key results:…

Quantum Physics · Physics 2025-06-02 Jun Tang , Dong-Qing Wang , Wei Zhong , Lan Zhou , Yu-Bo Sheng