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Related papers: Quantum phase estimation using path-symmetric enta…

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We propose a class of path-entangled photon Fock states for robust quantum optical metrology, imaging, and sensing in the presence of loss. We model propagation loss with beam-splitters and derive a reduced density matrix formalism from…

Quantum Physics · Physics 2009-03-13 Sean D. Huver , Christoph F. Wildfeuer , Jonathan P. Dowling

A method for exploring photon-number entangled states with weak nonlinearities is described. We show that it is possible to create and detect such entanglement at various scales, ranging from microscopic to macroscopic systems. In the…

Quantum Physics · Physics 2015-10-28 Yingqiu He , Dong Ding , Fengli Yan , Ting Gao

We propose a detection scheme for measuring the overlap of the quantum state of a weakly excited traveling-field mode with a desired reference quantum state, by successive mixing the signal mode with modes prepared in coherent states and…

Quantum Physics · Physics 2016-05-10 J. Clausen , M. Dakna , L. Knoll , D. -G. Welsch

Entangled photons have the remarkable ability to be more sensitive to signal and less sensitive to noise than classical light. Joint photons can sample an object collectively, resulting in faster phase accumulation and higher spatial…

Optics · Physics 2015-09-04 Chien-Hung Lu , Matthew Reichert , Xiaohang Sun , Jason W. Fleischer

Quantum entanglement and squeezing have significantly improved phase estimation and imaging in interferometric settings beyond the classical limits. However, for a wide class of non-interferometric phase imaging/retrieval methods vastly…

Entanglement is one of the fundamental properties of a quantum state and is a crucial differentiator between classical and quantum computation. There are many ways to define entanglement and its measure, depending on the problem or…

Quantum Physics · Physics 2025-01-07 Andrii Semenov , Niall Murphy , Simone Patscheider , Alessandra Bernardi , Elena Blokhina

In quantum phase estimation, the Heisenberg limit provides the ultimate accuracy over quasi-classical estimation procedures. However, realizing this limit hinges upon both the detection strategy employed for output measurements and the…

Quantum Physics · Physics 2024-07-23 Hanan Saidi , Hanane El Hadfi , Abdallah Slaoui , Rachid Ahl Laamara

Entangled resources enable quantum sensing that achieves Heisenberg scaling, a quadratic improvement on the standard quantum limit, but preparing large scale entangled states is challenging in the presence of decoherence. We present a…

Our study employs a connected correlation matrix to quantify Quantum Entanglement. The matrix encompasses all necessary measures for assessing the degree of entanglement between particles. We begin with a three-qubit state and involve…

Quantum Physics · Physics 2023-12-06 Xingyu Guo , Chen-Te Ma

We derive the optimal input states and the optimal quantum measurements for estimating the unitary action of a given symmetry group, showing how the optimal performance is obtained with a suitable use of entanglement. Optimality is defined…

Quantum Physics · Physics 2009-11-11 G. Chiribella , G. M. D'Ariano , M. F. Sacchi

We theoretically demonstrate a method for producing the maximally path-entangled state (1/Sqrt[2]) (|N,0> + exp[iN phi] |0,N>) using intensity-symmetric multiport beamsplitters, single photon inputs, and either photon-counting postselection…

Quantum Physics · Physics 2008-11-26 G. J. Pryde , A. G. White

Precision measurements are important across all fields of science. In particular, optical phase measurements can be used to measure distance, position, displacement, acceleration and optical path length. Quantum entanglement enables higher…

Quantum Physics · Physics 2009-11-13 Tomohisa Nagata , Ryo Okamoto , Jeremy L. O'Brien , Keiji Sasaki , Shigeki Takeuchi

Entanglement is recognized as a key resource for quantum computation and quantum cryptography. For quantum metrology, the use of entangled states has been discussed and demonstrated as a means of improving the signal-to-noise ratio. In…

Quantum Physics · Physics 2007-05-23 C. F. Roos , M. Chwalla , K. Kim , M. Riebe , R. Blatt

We investigate performances of pure continuous variable states in discriminating thermal and identity channels by comparing their M-copy error probability bounds. This offers us a simplified mathematical analysis for quantum target…

Quantum Physics · Physics 2009-07-10 A. R. Usha Devi , A. K. Rajagopal

We propose and experimentally demonstrate a method to directly measure the phase of biphoton states using an entangled mode as a collinear reference. The technique is demonstrated with entangled photonic spatial modes in the…

Quantum Physics · Physics 2024-06-18 Andrew A. Voitiv , Mark T. Lusk , Mark E. Siemens

Entanglement properties are routinely used to characterize phases of quantum matter in theoretical computations. For example the spectrum of the reduced density matrix, or so-called "entanglement spectrum", has become a widely used…

Mesoscale and Nanoscale Physics · Physics 2018-08-29 Kenny Choo , Curt W. von Keyserlingk , Nicolas Regnault , Titus Neupert

Entanglement is an important quantum resource to achieve high sensitive quantum metrology. However, the rapid decoherence of quantum entangled states, due to the unavoidable environment noise, result in practically the unwanted sharp drop…

Quantum Physics · Physics 2023-06-21 X. N. Feng , D. He , L. F. Wei

We give an analytical result for the quantum Fisher information of entangled coherent States in a lossy Mach-Zehnder Interferometer recently proposed by J. Joo et al. [Phys. Rev. Lett. 107, 083601(2011)]. For small loss of photons, we find…

Quantum Physics · Physics 2016-11-26 Xiaoxing Jing , Jing Liu , Wei Zhong , Xiaoguang Wang

Precise measurements are the key to advances in all fields of science. Quantum entanglement shows higher sensitivity than achievable by classical methods. Most physical quantities including position, displacement, distance, angle, and…

Quantum Physics · Physics 2017-07-05 Zhi-Yuan Zhou , Shi-Long Liu , Shi-Kai Liu , Yin-Hai Li , Dong-Sheng Ding , Guang-Can Guo , Bao-Sen Shi

We study the simultaneous estimation of multiple phases as a discretised model for the imaging of a phase object. We identify quantum probe states that provide an enhancement compared to the best quantum scheme for the estimation of each…

Quantum Physics · Physics 2013-09-10 Peter C. Humphreys , Marco Barbieri , Animesh Datta , Ian A. Walmsley