English
Related papers

Related papers: Practical Verification of Quantum Properties in Qu…

200 papers

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

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

It is known that if the quantum gates in a proposed quantum computer are so noisy that they are incapable of generating entanglement, then the device can be efficiently simulated classically. If the measurements and single particle…

Quantum Physics · Physics 2012-01-04 N. Ratanje , S. Virmani

An universal approximation technique for analysis of different characteristics of states of composite infinite-dimensional quantum systems is proposed and used to prove general results concerning the properties of correlation and…

Quantum Physics · Physics 2024-11-01 M. E. Shirokov

We present a class of entanglement identifiers which has the following experimentally friendly feature: once the expectation value of the identifier exceeds some definite limit, we can conclude the state is entangled, even if not all…

Quantum Physics · Physics 2013-08-22 Wieslaw Laskowski , Marcin Markiewicz , Tomasz Paterek , Ryszard Weinar

Evidencing the quantum nature of gravity through the entanglement of two masses has recently been proposed. Proposals using qubits to witness this entanglement can afford to bring two masses close enough so that the complete 1/r interaction…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Bin Yi , Urbasi Sinha , Dipankar Home , Anupam Mazumdar , Sougato Bose

Quantum computers show potential for achieving computational advantage over classical computers, with many candidate applications in combinatorial optimisation. We present an application level benchmarking framework for near-term quantum…

Unpredictability, or randomness, of the outcomes of measurements made on an entangled state can be certified provided that the statistics violate a Bell inequality. In the standard Bell scenario where each party performs a single…

Quantum Physics · Physics 2017-03-01 F. J. Curchod , M. Johansson , R. Augusiak , M. J. Hoban , P. Wittek , A. Acín

Quantum correlations exhibit behaviour that cannot be resolved with a local hidden variable picture of the world. In quantum information, they are also used as resources for information processing tasks, such as Measurement-based Quantum…

Quantum Physics · Physics 2011-02-10 Matty J. Hoban , Earl T. Campbell , Klearchos Loukopoulos , Dan E. Browne

Within the quantum networks scenario we introduce a single scheme allowing to certify three different types of composite projective measurements acting on a three-qubit Hilbert space: one constructed from genuinely entangled GHZ-like…

Quantum Physics · Physics 2025-05-20 Shubhayan Sarkar , Chandan Datta , Saronath Halder , Remigiusz Augusiak

Quantifying the entanglement and coherence of quantum systems is a topic of significant theoretical and practical interest. In this paper, we propose a method to evaluate lower bounds for several widely used coherence measures and genuine…

Quantum Physics · Physics 2025-08-19 Mingyu Liu , Xian Shi

The experimental verification of multipartite entangled states is essential for advancing quantum information processing. Entanglement witnesses (EWs) provide a widely used and experimentally accessible approach for detecting genuinely…

Quantum Physics · Physics 2025-09-03 Tomis Prajapati , Harsh Mehta , Shreya Banerjee , Prasanta K. Panigrahi , V. Narayanan

Quantum nonlocality offers a secure way to produce random numbers: their unpredictability is intrinsic and can be certified just by observing the statistic of the measurement outcomes, without assumptions on how they are produced. To do…

Benchmarking Quantum Process Units (QPU) at an application level usually requires considering the whole programming stack of the quantum computer. One critical task is the minor-embedding (resp. transpilation) step, which involves…

Quantum Physics · Physics 2024-08-02 Valentin Gilbert , Julien Rodriguez , Stéphane Louise

Quantum entanglement is an essential resource for quantum technologies, and the controlled swap test provides a versatile tool for its detection and quantification. Here, we propose a SWAP-based entanglement witness that applies to…

Quantum Physics · Physics 2025-12-24 Sebastiano Guaraldo , Sonia Mazzucchi , Alessio Baldazzi , Stefano Azzini , Lorenzo Pavesi

Quantum networks form the backbone of long-distance quantum information processing. Genuine multipartite entanglement (GME) serves as a key indicator of network performance and overall state quality. However, the widely used methods for…

Quantum Physics · Physics 2026-01-13 Jing-Tao Qiu , D. M. Tong , Xiao-Dong Yu

The experimental detection of multipartite entanglement usually requires a number of appropriately chosen local quantum measurements which are aligned with respect to a previously shared common reference frame. The latter, however, can be a…

Quantum Physics · Physics 2019-04-02 Andreas Ketterer , Nikolai Wyderka , Otfried Gühne

We study the entanglement properties of quantum hypergraph states of $n$ qubits, focusing on multipartite entanglement. We compute multipartite entanglement for hypergraph states with a single hyperedge of maximum cardinality, for…

Quantum Physics · Physics 2018-01-17 Maddalena Ghio , Daniele Malpetti , Matteo Rossi , Dagmar Bruß , Chiara Macchiavello

The rapid progress in quantum hardware is expected to make them viable tools for the study of quantum algorithms in the near term. The timeline to useful algorithmic experimentation can be accelerated by techniques that use many noisy shots…

In this paper, we investigate the critical efficiency of detectors to observe Bell nonlocality using multiple copies of the maximally entangled two-qubit state carried by a single pair of particles, such as hyperentangled states, and the…

Quantum Physics · Physics 2023-02-09 István Márton , Erika Bene , Tamás Vértesi