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Related papers: Generating optimal states for a homodyne Bell test

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Bell sampling is a simple yet powerful tool based on measuring two copies of a quantum state in the Bell basis, and has found applications in a plethora of problems related to stabiliser states and measures of magic. However, it was not…

Quantum Physics · Physics 2025-11-13 Jonathan Allcock , Joao F. Doriguello , Gábor Ivanyos , Miklos Santha

We show that the use of probabilistic noiseless amplification in entangled coherent state-based schemes for the test of quantum non locality provides substantial advantages. The threshold amplitude to falsify a Bell-CHSH non locality test,…

Quantum Physics · Physics 2013-05-14 G. Torlai , G. McKeown , P. Marek , R. Filip , H. Jeong , M. Paternostro , G. De Chiara

Bell inequality with self-testing property has played an important role in quantum information field with both fundamental and practical applications. However, it is generally challenging to find Bell inequalities with self-testing property…

Quantum Physics · Physics 2020-02-06 Qi Zhao , You Zhou

The efficient and reliable characterization of quantum states plays a vital role in most, if not all, quantum information processing tasks. In this work, we present a universally optimal protocol for verifying entangled states by employing…

Quantum Physics · Physics 2021-03-08 Ye-Chao Liu , Jiangwei Shang , Rui Han , Xiangdong Zhang

A protocol for teleportation of the state of a Bose-Einstein condensate trapped in a three-well potential is developed. The protocol uses hard-sphere cross-collision between the condensate modes as a means of generating entanglement. As…

Quantum Physics · Physics 2009-11-07 M. C. de Oliveira

Certifying the entanglement of quantum states with Bell inequalities allows one to guarantee the security of quantum information protocols independently of imperfections in the measuring devices. Here we present a similar procedure for…

Quantum Physics · Physics 2014-09-19 Adam Bennet , Tamás Vértesi , Dylan J. Saunders , Nicolas Brunner , G. J. Pryde

In the standard homodyne configuration, an unknown optical state is combined with a local oscillator (LO) on a beam splitter (BS). Good quadrature measurements require a high-amplitude LO and two high-efficiency photodiodes whose signals…

Quantum Physics · Physics 2023-06-01 Arik Avagyan

Lately, much interest has been directed towards designing setups that achieve decisive tests of local realism. Here we present Bell tests with measurements based on linear optical displacements and single-photon detection. The scheme…

Quantum Physics · Physics 2013-01-25 Jonatan Bohr Brask , Rafael Chaves

We investigate quantum measurement strategies capable of discriminating two coherent states probabilistically with significantly smaller error probabilities than can be obtained using non- probabilistic state discrimination. We apply a…

Quantum Physics · Physics 2010-10-12 Christoffer Wittmann , Ulrik L. Andersen , Masahiro Takeoka , Gerd Leuchs

A classical model is presented for the features of parametric down-conversion and homodyne detection relevant to recent proposed ``loophole-free'' Bell tests. The Bell tests themselves are uncontroversial: there are no obvious loopholes…

Quantum Physics · Physics 2007-05-23 Caroline H Thompson

We report an experimental demonstration of effective entanglement in a prepare&measure type of quantum key distribution protocol. Coherent polarization states and heterodyne measurement to characterize the transmitted quantum states are…

Quantum Physics · Physics 2009-11-13 S. Lorenz , J. Rigas , M. Heid , U. L. Andersen , N. Lütkenhaus , G. Leuchs

It is known that the quantum fidelity, as a measure of the closeness of two quantum states, is operationally equivalent to the minimal overlap of the probability distributions of the two states over all possible POVMs; the POVM realizing…

Quantum Physics · Physics 2009-11-10 Hyunchul Nha , H. J. Carmichael

Experiments showing the violation of Bell inequalities have formed our belief that the world at its smallest is genuinely non-local. While many non-locality experiments use the first quantised picture, the physics of fields of…

Quantum Physics · Physics 2013-05-29 Libby Heaney , Janet Anders

We emphasize the Bell state analyzer, a beamsplitter, as an efficient means of detecting two-photon polarization entanglement. Whereas the optimal entanglement witness for spatially separated photons requires coordinated measurement in…

Quantum Physics · Physics 2015-07-14 Brian P. Williams , Travis S. Humble

Violation of Bell inequality is a prominent detection method for quantum correlations present in composite quantum systems, both in finite and infinite dimensions. We investigate the consequence on the violation of local realism based on…

Quantum Physics · Physics 2018-12-05 Saptarshi Roy , Titas Chanda , Tamoghna Das , Aditi Sen De , Ujjwal Sen

Self-testing was originally introduced as a device-independent method of certification of entangled quantum states and local measurements performed on them. Recently, in [F. Baccari \textit{et al.}, arXiv:2003.02285] the notion of state…

Quantum Physics · Physics 2021-07-02 Owidiusz Makuta , Remigiusz Augusiak

Experimental violations of Bell inequalities are in general vulnerable to so-called "loopholes." In this work, we analyse the characteristics of a loophole-free Bell test with photons, closing simultaneously the locality, freedom-of-choice,…

Quantum Physics · Physics 2016-03-11 Johannes Kofler , Marissa Giustina , Jan-Åke Larsson , Morgan W. Mitchell

Kerr parametric oscillators (KPOs) have attracted increasing attention in terms of their application to quantum information processing and quantum simulations. The state preparation and measurement of KPOs are typical requirements when they…

Quantum Physics · Physics 2022-08-10 Yuta Suzuki , Shohei Watabe , Shiro Kawabata , Shumpei Masuda

A solid state device to discriminate all the four Bell states is proposed. The device is composed of controlled absorption crystals, rotators, and retarders. The controlled absorption, where the state of one photon affects the absorption of…

Quantum Physics · Physics 2007-05-23 A. Tomita

We present a new asymptotic bipartite entanglement distillation protocol that outperforms all existing asymptotic schemes. This protocol is based on the breeding protocol with the incorporation of two-way classical communication. Like…

Quantum Physics · Physics 2009-11-13 Erik Hostens , Jeroen Dehaene , Bart De Moor