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Related papers: Closing the detection loophole in tripartite Bell …

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We present a three-qubit quantum state tomography scheme requiring a set of 17 measurement settings, significantly reducing the experimental overhead compared to the conventional 63 Pauli measurement settings. Using IBM's 127-qubit…

Quantum Physics · Physics 2026-02-03 H. Talath , B. P. Govindaraja , B. G. Divyamani , Akshata Shenoy H. , A. R. Usha Devi , Sudha

We present a set of Bell inequalities that gives rise to a finer classification of the entanglement for tripartite systems. These inequalities distinguish three possible bi-separable entanglements for three-qubit states. The three Bell…

Quantum Physics · Physics 2007-05-23 Bao-Zhi Sun , Shao-Ming Fei

Recently, V\'{e}rtesi and Bene [Phys. Rev. A. {\bf 82}, 062115 (2010)] derived a two-qubit Bell inequality, $I_{CH3}$, which they show to be maximally violated only when more general positive operator valued measures (POVMs) are used…

Quantum Physics · Physics 2015-06-05 J. F. Barra , E. S. Gómez , G. Cañas , W. A. T. Nogueira , L. Neves , G. Lima

It is well-known that in certain scenarios weakly entangled states can generate stronger nonlocal effects than their maximally entangled counterparts. In this paper, we consider violations of the CHSH Inequality when one party has…

Quantum Physics · Physics 2018-06-13 Daniel Dilley , Eric Chitambar

According to recent reports, the last loopholes in testing Bell's inequality are closed. It is argued that the really important task in this field has not been tackled yet and that the leading experiments claiming to close locality and…

Quantum Physics · Physics 2007-05-23 L. Vaidman

The demonstration and use of nonlocality, as defined by Bell's theorem, rely strongly on dealing with non-detection events due to losses and detector inefficiencies. Otherwise, the so-called detection loophole could be exploited. The only…

Quantum Physics · Physics 2016-01-20 Gilles Pütz , Nicolas Gisin

We consider a possible detector-efficiency loophole in experiments that detect entanglement via the local measurement of witness operators. Here, only local properties of the detectors are known. We derive a general threshold for the…

Quantum Physics · Physics 2007-07-18 Patrick Skwara , Hermann Kampermann , Matthias Kleinmann , Dagmar Bruss

We construct the tripartite Bell-type inequalities of product states for l1-norm of coherence, relative entropy of coherence and skew information. Some three-qubit entangled states violate these inequalities. Particulary, the tripartite…

Quantum Physics · Physics 2016-10-25 L. Qiu , Z. Liu , F. Pan

In order to faithfully detect the state of an individual two-state quantum system (qubit) realized using, for example, a trapped ion or atom, state selective scattering of resonance fluorescence is well established. The simplest way to read…

Quantum Physics · Physics 2015-04-23 Sabine Wölk , Christian Piltz , Theeraphot Sriarunothai , Christof Wunderlich

We derive a Bell inequality based on a generalized quasiprobability function which is parameterized by one non-positive real value. Two types of known Bell inequalities formulated in terms of the Wigner and Q functions are included as…

Quantum Physics · Physics 2009-08-06 Seung-Woo Lee , Hyunseok Jeong , Dieter Jaksch

We propose a new method for detecting entanglement of two qubits and discuss its relation with the Clauser-Horne-Shimony-Holt (CHSH) Bell inequality. Without the need for full quantum tomography for the density matrix we can experimentally…

Quantum Physics · Physics 2007-05-23 Kai Chen , Ling-An Wu

The demonstration and use of nonlocality, as defined by Bell's theorem, rely strongly on dealing with non-detection events due to losses and detectors' inefficiencies. Otherwise, the so-called detection loophole could be exploited. The only…

In a photonic realization of qubits the implementation of quantum logic is rather difficult due the extremely weak interaction on the few photon level. On the other hand, in these systems interference is available to process the quantum…

Quantum Physics · Physics 2015-06-26 John Calsamiglia , Norbert Lütkenhaus

We examine the problem of exhibiting Bell nonlocality for a two-qudit entangled pure state using a randomly chosen set of mutually unbiased bases (MUBs). Interestingly, even if we employ only two-setting Bell inequalities, we find a…

Quantum Physics · Physics 2022-07-19 Gelo Noel M. Tabia , Varun Satya Raj Bavana , Shih-Xian Yang , Yeong-Cherng Liang

A proof of Bell's theorem without inequalities valid for both inequivalent classes of three-qubit entangled states under local operations assisted by classical communication, namely Greenberger-Horne-Zeilinger (GHZ) and W, is described.…

Quantum Physics · Physics 2009-07-28 Adan Cabello

Recently Yu and Sun [Int. J. Theor. Phys. DOI 10.1007/s10773-014-2360-x] have presented probabilistic teleportation of 3-qubit cat state via 6-qubit cluster state. The success probability depends on absolute value of only two of the…

Quantum Physics · Physics 2014-12-25 Anindita Banerjee , Chitra Shukla

We reduce the extra qubits needed for two fault-tolerant quantum computing protocols: error correction, specifically syndrome bit measurement, and cat state preparation. For distance-three fault-tolerant syndrome extraction, we show an…

Quantum Physics · Physics 2023-10-25 Prithviraj Prabhu , Ben W. Reichardt

We investigate three superconducting flux qubits coupled in a loop. In this setup, tripartite entanglement can be created in a natural, controllable, and stable way. Both generic kinds of tripartite entanglement -the W type as well as the…

Quantum Physics · Physics 2015-05-14 Johannes Ferber , Frank K. Wilhelm

We have determined numerically the maximum quantum violation of over 100 tight bipartite Bell inequalities with two-outcome measurements by each party on systems of up to four dimensional Hilbert spaces. We have found several cases,…

Quantum Physics · Physics 2009-11-13 K. F. Pál , T. Vértesi

We report on a test of Bell inequalities using a non-maximally entangled state, which represents an important step in the direction of eliminating the detection loophole. The experiment is based on the creation of a polarisation entangled…

Quantum Physics · Physics 2007-05-23 G. Brida , M. Genovese , C. Novero , E. Predazzi