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Related papers: Estimating entanglement of unknown states

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Experimental determination of an unknown quantum state usually requires several incompatible measurements. However, it is also possible to determine the full quantum state from a single, repeated measurement. For this purpose, the quantum…

Quantum Physics · Physics 2008-03-25 Xinhua Peng , Jiangfeng Du , Dieter Suter

Negativity is regarded as an important measure of entanglement in quantum information theory. In contrast to other measures of entanglement, it is easily computable for bipartite states in arbitrary dimensions. In this paper, based on the…

Quantum Physics · Physics 2010-04-30 Yong-Cheng Ou , Mark S. Byrd

Entangled many-body states are an essential resource for quantum computing and interferometry. Determining the type of entanglement present in a system usually requires access to an exponential number of parameters. We show that in the case…

Quantum Physics · Physics 2014-11-17 Michael Walter , Brent Doran , David Gross , Matthias Christandl

Quantum entanglement is a key resource in quantum computing and quantum information processing tasks. However, its quantification remains a major challenge since it cannot be directly extracted from physical observables. To address this…

Quantum Physics · Physics 2025-12-29 Shruti Aggarwal , Trasha Gupta , R. K. Agrawal , S. Indu

Entanglement is a key ingredient for quantum technologies and a fundamental signature of quantumness in a broad range of phenomena encompassing many-body physics, thermodynamics, cosmology, and life sciences. For arbitrary multiparticle…

Quantum Physics · Physics 2016-10-24 Marco Cianciaruso , Thomas R. Bromley , Gerardo Adesso

Quantum entanglement is the key resource for quantum information processing. Device-independent certification of entangled states is a long standing open question, which arouses the concept of self-testing. The central aim of self-testing…

The entanglement detection via local measurements can be experimentally implemented. Based on mutually unbiased measurements and general symmetric informationally complete positive-operator-valued measures, we present separability criteria…

Quantum Physics · Physics 2018-03-30 Shu-Qian Shen , Ming Li , Xianqing Li-Jost , Shao-Ming Fei

Entangled physical systems are an important resource in quantum information. Some authors claim that in fact all quantum states are entangled. In this paper we show that this claim is incorrect and we discuss in operational way differences…

Quantum Physics · Physics 2016-10-07 Marian Kupczynski

Entanglement is a key resource to demonstrate quantum advantage over classical strategies. Entanglement in quantum states is one of the most well-explored areas in quantum physics. However, a rigorous approach to understanding and detecting…

Quantum Physics · Physics 2025-02-12 Shubhayan Sarkar

There exists, in general, a convex set of quantum state estimators that maximize the likelihood for informationally incomplete data. We propose an estimation scheme, catered to measurement data of this kind, to search for the exact…

We frame entanglement detection as a problem of random variable inference to introduce a quantitative method to measure and understand whether entanglement witnesses lead to an efficient procedure for that task. Hence we quantify how many…

Quantum Physics · Physics 2023-08-16 Paulo J. Cavalcanti , Giovanni Scala , Antonio Mandarino , Cosmo Lupo

Multipartite entanglement is very poorly understood despite all the theoretical and experimental advances of the last decades. Preparation, manipulation and identification of this resource is crucial for both practical and fundamental…

Quantum Physics · Physics 2015-09-28 G. H. Aguilar , S. P. Walborn , P. H. Souto Ribeiro , L. C. Céleri

Determining the state of a quantum system is a consuming procedure. For this reason, whenever one is interested only in some particular property of a state, it would be desirable to design a measurement setup that reveals this property with…

Quantum Physics · Physics 2017-06-02 Claudio Carmeli , Teiko Heinosaari , Jussi Schultz , Alessandro Toigo

Entanglement is a central feature of quantum theory. Mathematical properties and physical applications of pure state entanglement make it a template to study quantum correlations. However, an extension of entanglement measures to mixed…

Quantum Physics · Physics 2017-07-19 Aharon Brodutch , Daniel R. Terno

Quantifying entanglement for multipartite quantum state is a crucial task in many aspects of quantum information theory. Among all the entanglement measures, relative entropy of entanglement $E_{R}$ is an outstanding quantity due to its…

Quantum Physics · Physics 2020-10-30 Shi-Yao Hou , Chenfeng Cao , D. L. Zhou , Bei Zeng

I give an overview of some of the most used measures of entanglement. To make the presentation self-contained, a number of concepts from quantum information theory are first explained. Then the structure of bipartite entanglement is studied…

Quantum Physics · Physics 2007-05-23 Geir Ove Myhr

Entanglement, the essential resource in quantum information processing, should be witnessed in many tasks such as quantum computing and quantum communication. The conventional entanglement witness method, relying on an idealized…

Quantum Physics · Physics 2014-04-17 Ping Xu , Xiao Yuan , Luo-Kan Chen , He Lu , Xing-Can Yao , Xiongfeng Ma , Yu-Ao Chen , Jian-Wei Pan

How much information about an unknown quantum state can be obtained by a measurement? We propose a model independent answer: the information obtained is equal to the minimum entropy of the outputs of the measurement, where the minimum is…

Quantum Physics · Physics 2009-10-31 S. Massar , S. Popescu

Entanglement does not correspond to any observable and its evaluation always corresponds to an estimation procedure where the amount of entanglement is inferred from the measurements of one or more proper observables. Here we address…

Quantum Physics · Physics 2009-11-13 Marco G. Genoni , Paolo Giorda , Matteo G. A. Paris

Entanglement, a puzzle since Einstein's time, has become increasingly crucial with the rise of quantum computation. But what exactly is it? Historically , entanglement can be precisely defined, but only negatively. In this article, we…

Quantum Physics · Physics 2024-03-26 Chon-Fai Kam , Zhong-Tang Wu