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Related papers: Benchmarks of Nonclassicality for Qubit Arrays

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By introducing a semi-honest third party (TP), we propose in this paper a novel QPC protocol using (n+1)- qubit (n \ge 2) Greenberger-Horne-Zeilinger (GHZ) states as information carriers. The parameter n not only determines the number of…

Cryptography and Security · Computer Science 2020-08-20 Zhaoxu Ji , Peiru Fan , Huanguo Zhang , Houzhen Wang

We present a local hidden-variable model supplemented by classical communication that reproduces the quantum-mechanical predictions for measurements of all products of Pauli operators on an n-qubit GHZ state (or "cat state"). The simulation…

Quantum Physics · Physics 2007-05-23 Tracey E. Tessier , Ivan H. Deutsch , Carlton M. Caves

In the literature on $K$-locality ($K\geq2$) networks, the local hidden variables are strictly distributed in the specific observers rather than the whole ones. Regarding genuine Bell locality, all local hidden variables, as classical…

Quantum Physics · Physics 2023-06-28 Li-Yi Hsu

Entanglement of quasiclassical (coherent) states of two harmonic oscillators leads to striking quantum effects and is useful for quantum technologies. These effects and applications are closely related to nonlocal correlations inherent in…

Quantum Physics · Physics 2019-05-14 Zhi-Rong Zhong , Jian-Qi Sheng , Li-Hua Lin , Shi-Biao Zheng

Bipartite and multipartite entangled states are basic ingredients for constructing quantum networks and their accurate verification is crucial to the functioning of the networks, especially for untrusted networks. Here we propose a simple…

Quantum Physics · Physics 2021-12-28 Yun-Guang Han , Zihao Li , Yukun Wang , Huangjun Zhu

With improved gate calibrations reducing unitary errors, we achieve a benchmarked single-qubit gate fidelity of 99.95% with superconducting qubits in a circuit quantum electrodynamics system. We present a method for distinguishing between…

Quantum Physics · Physics 2016-01-13 Sarah Sheldon , Lev S. Bishop , Easwar Magesan , Stefan Filipp , Jerry M. Chow , Jay M. Gambetta

The development of complex circuits for practical applications in the current quantum computing ecosystem is based on basic primitives such as Bell states, which provide superposition, entanglement, and coherence. The range of…

Quantum Physics · Physics 2026-04-07 Hillol Biswas

Entanglement depth quantifies how many qubits share genuine multipartite entanglement, but certification typically relies on tailored witnesses or full tomography, both of which scale poorly with system size. We recast entanglement-depth…

Quantum Physics · Physics 2025-12-16 Marcin Płodzień

The existence of correlations between the parts of a quantum system on the one hand, and entanglement between them on the other, are different properties. Yet, one intuitively would identify strong $N$-party correlations with $N$-party…

Quantum Physics · Physics 2020-02-12 Christopher Eltschka , Jens Siewert

In device-independent quantum information, correlations between local measurement outcomes observed by spatially separated parties in a Bell test play a fundamental role. Even though it is long-known that the set of correlations allowed in…

We present a brief historical introduction to the topic of Bell's theorem. Next we present the surprising features of the three particle Greenberger-Horne-Zeilinger (GHZ) states. Finally we shall present a method of analysis of the GHZ…

Quantum Physics · Physics 2007-05-23 D. Kaszlikowski , M. Zukowski

We explore the subtle relationships between partial separability and entanglement of subsystems in multiqubit quantum states and give experimentally accessible conditions that distinguish between various classes and levels of partial…

Quantum Physics · Physics 2008-09-03 Michael Seevinck , Jos Uffink

The ubiquity of stabilizer circuits in the design and operation of quantum computers makes techniques to verify their correctness essential. The simulation of stabilizer circuits, which aims to replicate their behavior using a classical…

Quantum Physics · Physics 2023-09-19 Vadym Kliuchnikov , Michael Beverland , Adam Paetznick

Greenberger-Horne-Zeilinger (GHZ) theorem asserts that there is a set of mutually commuting nonlocal observables with a common eigenstate on which those observables assume values that refute the attempt to assign values only required to…

Quantum Physics · Physics 2007-05-23 Li Tang , Jie Zhong , Yaofeng Ren , Mingsheng Zhan , Zeqian Chen

Many-particle entanglement is a key resource for achieving the fundamental precision limits of a quantum sensor. Optical atomic clocks, the current state-of-the-art in frequency precision, are a rapidly emerging area of focus for…

Separability and entanglement for n-qubits systems are quantified by using Hilbert-Schmidt (HS) decompositions in which the density matrices are decomposed into various terms representing certain one qubit, two-qubits,and larger qubits…

Quantum Physics · Physics 2016-02-23 Y. Ben-Aryeh

We introduce an inductive $n$-qubit pure-state estimation method. This is based on projective measurements on states of $2n+1$ separable bases or $2$ entangled bases plus the computational basis. Thus, the total number of measurement bases…

Quantum Physics · Physics 2022-05-17 L. Pereira , L. Zambrano , A. Delgado

We again consider (as in a companion paper) an entangled two-particle state that is produced from two independent down-conversion sources by the process of "entanglement-swapping", so that the particles have never met. We show that there is…

Quantum Physics · Physics 2008-08-01 Daniel Greenberger , Michael Horne , Anton Zeilinger , Marek Zukowski

Experimentally quantifying entanglement and coherence are extremely important for quantum resource theory. However, because the quantum state tomography requires exponentially growing measurements with the number of qubits, it is hard to…

Quantum Physics · Physics 2020-05-13 Yue Dai , Yuli Dong , Zhenyu Xu , Wenlong You , Chengjie Zhang , Otfried Gühne

Quantum entanglement is a fundamental property of coherent quantum states and an essential resource for quantum computing. While two-qubit entanglement has been demonstrated for spins in silicon, creation of multipartite entanglement, a…

Mesoscale and Nanoscale Physics · Physics 2021-06-17 Kenta Takeda , Akito Noiri , Takashi Nakajima , Jun Yoneda , Takashi Kobayashi , Seigo Tarucha