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Related papers: Iso-entangled bases and joint measurements

200 papers

Conventional methods of measuring entanglement in a two-qubit photonic mixed state require the detection of both qubits. We generalize a recently introduced method which does not require the detection of both qubits, by extending it to…

Quantum Physics · Physics 2023-11-30 Salini Rajeev , Mayukh Lahiri

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

We propose a simple and realizable method using a two-particle interferometer for the experimental measurement of pairwise entanglement, assuming some prior knowledge about the quantum state. The basic idea is that the properties of the…

Quantum Physics · Physics 2007-05-23 Jian-Ming Cai , Zheng-Wei Zhou , Guang-Can Guo

Harnessing the advantages of shared entanglement for sending quantum messages often requires the implementation of complex two-particle entangled measurements. We investigate entanglement advantages in protocols that use only the simplest…

Entanglement not only plays a crucial role in quantum technologies, but is key to our understanding of quantum correlations in many-body systems. However, in an experiment, the only way of measuring entanglement in a generic mixed state is…

Quantum Physics · Physics 2018-10-16 Johnnie Gray , Leonardo Banchi , Abolfazl Bayat , Sougato Bose

Scrambling unitary dynamics in a quantum system transmutes local quantum information into a non-local web of correlations which manifests itself in a complex spatio-temporal pattern of entanglement. In such a context, we show there can…

Quantum Physics · Physics 2025-06-02 Alan Sherry , Sthitadhi Roy

We review and discuss the potential of using measurement-based elements in quantum communication schemes, where certain tasks are realized with the help of entangled resource states that are processed by measurements. We consider long-range…

Quantum Physics · Physics 2016-09-27 M. Zwerger , H. J. Briegel , W. Dür

In this work we make progress in understanding the relationship between learning models with access to entangled, separable and statistical measurements in the quantum statistical query (QSQ) model. To this end, we show the following…

Quantum Physics · Physics 2023-12-12 Srinivasan Arunachalam , Vojtech Havlicek , Louis Schatzki

Joint measurements of qubit observables have recently been studied in conjunction with quantum information processing tasks such as cloning. Considerations of such joint measurements have until now been restricted to a certain class of…

Quantum Physics · Physics 2008-06-10 Paul Busch , Teiko Heinosaari

Quantum correlations and entanglement are fundamental resources for quantum information and quantum communication processes. Developments in these fields normally assume these resources stable and not susceptible of distortion. That is not…

Quantum Physics · Physics 2017-06-13 Francisco Delgado

The preparation of long-range entangled (LRE) states via quantum measurements is a promising strategy, yet its stability against realistic, non-commuting measurement noise remains a critical open question. Here, we systematically…

Quantum Physics · Physics 2025-08-22 Yuanchen Zhao , Li Rao , Dong E. Liu

Quantum information theory and quantum computing are theoritical basis of quantum computers. Thanks to entanglement, quantum mechanical systems are provisioned to realize many information processing problems faster than classical…

Quantum Physics · Physics 2017-04-19 Volkan Erol

By using finite resolution measurements it is possible to simultaneously obtain noisy information on two non-commuting polarization components of a single photon. This method can be applied to a pair of entangled photons with polarization…

Quantum Physics · Physics 2007-05-23 Holger F. Hofmann

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

Although quantum entanglement has already been verified experimentally and applied in quantum computing, quantum sensing and quantum networks, most of the existing measures cannot characterize the entanglement faithfully. In this work, by…

Quantum Physics · Physics 2023-01-10 Zhi-Xiang Jin , Shao-Ming Fei , Xianqing Li-Jost , Cong-Feng Qiao

The evolution of the quantum state of a system upon measurement results in state update. In this work, we investigate the characterization of updated states of multi-partite entangled qubit states with non-destructive weak measurements,…

Quantum Physics · Physics 2025-02-18 Jawad Allam , Alex Matzkin

We construct a single observable measurement of which mean value on four copies of an {\it unknown} two-qubit state is sufficient for unambiguous decision whether the state is separable or entangled. In other words, there exists a universal…

Quantum Physics · Physics 2015-06-26 Remigiusz Augusiak , Maciej Demianowicz , Pawel Horodecki

While all bipartite pure entangled states are known to generate correlations violating a Bell inequality, and are therefore nonlocal, the quantitative relation between pure-state entanglement and nonlocality is poorly understood. In fact,…

Quantum Physics · Physics 2018-08-14 Victoria Lipinska , Florian Curchod , Alejandro Máttar , Antonio Acín

The problem of inferring the outcome of a simultaneous measurement of two non-commuting observables is addressed. We show that for certain pairs with dense spectra, precise inferences of the measurement outcomes are possible in pre-and…

Quantum Physics · Physics 2007-10-16 Alonso Botero

Discrete structures in Hilbert space play a crucial role in finding optimal schemes for quantum measurements. We solve the problem whether a complete set of five iso-entangled mutually unbiased bases exists in dimension four, providing an…

Quantum Physics · Physics 2020-03-10 Jakub Czartowski , Dardo Goyeneche , Markus Grassl , Karol Życzkowski