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Entanglement is a fundamental resource for many applications in quantum information processing. Here, we investigate how quantum transport in simple quantum graphs, modeled as controlled two-level quantum systems, can be utilized to…

Quantum Physics · Physics 2025-10-24 Alison A. Silva , D. Bazeia , Fabiano M. Andrade

Coherent manipulation of an increasing number of qubits for the generation of entangled states has been an important goal and benchmark in the emerging field of quantum information science. The multiparticle entangled states serve as…

Quantum entanglement is one of the most important resources in quantum information. In recent years, the research of quantum entanglement mainly focused on the increase in the number of entangled qubits or the high-dimensional entanglement…

This thesis is an attempt to enhance understanding of the following questions A- Given a multipartite quantum state (possibly mixed), how to find out whether it is entangled or separable? (Detection of entanglement.) B- Given an entangled…

Quantum Physics · Physics 2009-05-05 Ali Saif M. Hassan

As superconducting qubits continue to advance technologically, the realization of quantum algorithms from theoretical abstraction to physical implementation requires knowledge of both quantum circuit construction as well as hardware…

Quantum Physics · Physics 2021-01-25 Daniel Koch , Brett Martin , Saahil Patel , Laura Wessing , Paul M. Alsing

Graph states represent a significant class of multi-partite entangled quantum states with applications in quantum error correction, quantum communication, and quantum computation. In this work, we introduce a novel formalism called the…

Quantum Physics · Physics 2025-07-16 Sameer Sharma

We implement a protocol to determine the degree of entanglement between a qubit and the rest of the system on a quantum computer. The protocol is based on results obtained in paper [Frydryszak et al. (2017)]. This protocol is tested on a…

Quantum Physics · Physics 2020-06-24 A. R. Kuzmak , V. M. Tkachuk

We report the preparation and verification of a genuine 12-qubit entanglement in a superconducting processor. The processor that we designed and fabricated has qubits lying on a 1D chain with relaxation times ranging from 29.6 to 54.6…

Entanglement lies at the core of quantum algorithms designed to solve problems that are intractable by classical approaches. One such algorithm, quantum annealing (QA), provides a promising path to a practical quantum processor. We have…

In recent years, quantum computing has promised a revolution in computing performance, based on massive parallelism enabled by many entangled qubits. Josephson junction integrated circuits have emerged as the key technology to implement…

Superconductivity · Physics 2014-08-26 Alan M. Kadin , Steven B. Kaplan

Quantum computers have the potential to solve certain interesting problems significantly faster than classical computers. To exploit the power of a quantum computation it is necessary to perform inter-qubit operations and generate entangled…

Mesoscale and Nanoscale Physics · Physics 2013-04-09 Michael D. Shulman , Oliver E. Dial , Shannon P. Harvey , Hendrik Bluhm , Vladimir Umansky , Amir Yacoby

We prove experimentally the predicted existence of a three-qubit quantum state with genuine multipartite entanglement which can be certified solely from its separable two-qubit reduced density matrices. The qubits are encoded into different…

Quantum Physics · Physics 2020-08-05 Michal Mičuda , Robert Stárek , Jan Provazník , Olga Leskovjanová , Ladislav Mišta,

Quantum entanglement is a key resource in quantum computing and quantum information processing tasks. However, its quantification remains a major challenge since it cannot be directly extracted from physical observables. To address this…

Quantum Physics · Physics 2025-12-29 Shruti Aggarwal , Trasha Gupta , R. K. Agrawal , S. Indu

Traditionally, quantum entanglement has played a central role in foundational discussions of quantum mechanics. The measurement of correlations between entangled particles can exhibit results at odds with classical behavior. These…

Mesoscale and Nanoscale Physics · Physics 2012-03-15 L. DiCarlo , M. D. Reed , L. Sun , B. R. Johnson , J. M. Chow , J. M. Gambetta , L. Frunzio , S. M. Girvin , M. H. Devoret , R. J. Schoelkopf

We report on deterministic generation of 18-qubit genuinely entangled Greenberger-Horne-Zeilinger (GHZ) state and multi-component atomic Schr\"{o}dinger cat states of up to 20 qubits on a quantum processor, which features 20 superconducting…

We address the question of whether or not global entanglement of a quantum state can be inferred from local properties. Specifically, we are interested in genuinely multiparticle entangled states whose two-body marginals are all separable,…

Quantum Physics · Physics 2018-12-05 Marius Paraschiv , Nikolai Miklin , Tobias Moroder , 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 entanglement of graph states up to eight qubits is calculated in the regime of iteration calculation. The entanglement measures could be the relative entropy of entanglement, the logarithmic robustness or the geometric measure. All 146…

Quantum Physics · Physics 2015-05-14 Xiao-yu Chen

We investigate the entanglement properties of quantum states associated with directed graphs. Using a measure derived from the Fubini-Study metric, we quantitatively relate multipartite entanglement to the local connectivity of the graph.…

Quantum Physics · Physics 2025-09-08 Lucio De Simone , Roberto Franzosi

We study the entanglement properties of randomized mixed hypergraph states, extending the concept of randomized mixed graph states to encompass hypergraph-based quantum states. In our model, imperfect generalized multi-qubit gates are…

Quantum Physics · Physics 2026-04-13 Vinícius Salem , Alison A. Silva , Fabiano M. Andrade