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Related papers: Benchmarks of Nonclassicality for Qubit Arrays

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Hybrid quantum-classical algorithms provide ways to use noisy intermediate-scale quantum computers for practical applications. Expanding the portfolio of such techniques, we propose a quantum circuit learning algorithm that can be used to…

As quantum processors grow, new performance benchmarks are required to capture the full quality of the devices at scale. While quantum volume is an excellent benchmark, it focuses on the highest quality subset of the device and so is unable…

We introduce a protocol to classify three-qubit pure states into different entanglement classes and implement it on an NMR quantum processor. The protocol is designed in such a way that the experiments performed to classify the states can…

Quantum Physics · Physics 2024-11-07 Vaishali Gulati , Arvind , Kavita Dorai

We study the robustness of the GHZ (or ``cat'') class of multi-partite states under decoherence. The noise model is described by a general completely positive map for qubits independently coupled to the environment. In particular, the…

Quantum Physics · Physics 2007-05-23 Somshubhro Bandyopadhyay , Daniel A. Lidar

Fidelity estimation is a crucial component for the quality control of entanglement distribution networks. This work studies a scenario in which multiple nodes share noisy Greenberger-Horne-Zeilinger (GHZ) states. Due to the collapsing…

Quantum Physics · Physics 2024-08-20 Liangzhong Ruan

Various algorithms have been developed to simulate quantum circuits on classical hardware. Among the most prominent are approaches based on \emph{stabilizer decompositions} and \emph{tensor network contraction}. In this work, we present a…

Quantum Physics · Physics 2026-03-09 Julien Codsi , Tuomas Laakkonen

The genuine concurrence is a standard quantifier of multipartite entanglement, detection and quantification of which still remains a difficult problem from both theoretical and experimental point of view. Although many efforts have been…

Quantum Physics · Physics 2021-05-14 Kateřina Jiráková , Artur Barasiński , Antonín Černoch , Karel Lemr , Jan Soubusta

We present a class of observables which are suitable for determining the fidelity of a state to the multipartite Greenberger-Horne-Zeilinger (GHZ) state. Given an expectation value of an observable belonging to the class, we give a simple…

Quantum Physics · Physics 2015-06-26 Koji Nagata , Masato Koashi , Nobuyuki Imoto

We introduce a single real-valued functional $I(\vec{n}_1,\vec{n}_2)$, built from four three-qubit correlation expectation values, that turns the Greenberger--Horne--Zeilinger (GHZ) algebraic paradox into a \emph{quantitative} witness of…

Quantum Physics · Physics 2026-05-05 Shengjun Wu , Kaichen Zhong , Jeffery Wu

We propose a scalable and deterministic protocol for growing large multi-qubit states starting from two-qubit non-maximally entangled pure states, where the bipartite entanglement in the resultant state is higher than the maximum of the…

Quantum Physics · Physics 2026-04-28 Harikrishnan K J , Amit Kumar Pal

In this paper, we show that there are eight distinct forms of the Greenberger-Horne-Zeilinger (GHZ) argument for the four-qubit cluster state $|\phi_4>$ and forty eight distinct forms for the five-qubit cluster state $|\phi_5>$ in the case…

Quantum Physics · Physics 2008-12-31 Li Tang , Zeqian Chen , Zeng-Bing Chen

Quantum self-testing is a device-independent way to certify quantum states and measurements using only the input-output statistics, with minimal assumptions about the quantum devices. Because of the high demand on tolerable noise, however,…

Benchmarking large-scale quantum gates, typically involving multiple native two-qubit and singlequbit gates, is crucial in quantum computing. Global fidelity, encompassing information about intergate correlations, offers a comprehensive…

Detecting genuine multipartite entanglement (GME) is a state-characterization task that benchmarks coherence and experimental control in quantum systems. Existing GME tests often require joint measurements on many qubits, posing challenges…

Quantum Physics · Physics 2026-02-18 Nicky Kai Hong Li , Xi Dai , Manuel H. Muñoz-Arias , Kevin Reuer , Marcus Huber , Nicolai Friis

Gate model quantum computers promise to solve currently intractable computational problems if they can be operated at scale with long coherence times and high fidelity logic. Neutral atom hyperfine qubits provide inherent scalability due to…

Graph states -- one of the most representative families of multipartite entangled states, are important resources for multiparty quantum communication, quantum error correction, and quantum computation. Device-independent certification of…

Quantum Physics · Physics 2022-01-12 Jia-Min Xu , Qing Zhou , Yu-Xiang Yang , Zi-Mo Cheng , Xin-Yu Xu , Zhi-Cheng Ren , Xi-Lin Wang , Hui-Tian Wang

Composite quantum states can be classified by how they behave under local unitary transformations. Each quantum state has a stabilizer subgroup and a corresponding Lie algebra, the structure of which is a local unitary invariant. In this…

Quantum Physics · Physics 2008-10-12 Scott N. Walck , David W. Lyons

Current noise levels in physical realizations of qubits and quantum operations limit the applicability of conventional methods to characterize entanglement. In this adverse scenario, we follow a quantum variational approach to estimate the…

Quantum Physics · Physics 2022-09-16 A. D. Muñoz-Moller , L. Pereira , L. Zambrano , J. Cortés-Vega , A. Delgado

Bell nonlocality provides a device-independent (DI) way to certify quantum randomness, based on which true random numbers can be extracted from the observed correlations without detail characterizations on devices for quantum state…

Quantum Physics · Physics 2026-01-27 Shuai Zhao , Rong Wang , Qi Zhao

While the adiabatic exchange of Majorana zero modes (MZMs) enables a non-universal set of geometrically protected gates, realising an experimental implementation of MZM braiding remains challenging. In an alternative proposal, charge-parity…

Quantum Physics · Physics 2025-07-29 Matthew Brooks , Foster Sabatino , Charles Tahan , Silas Hoffman