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The characterization of genuine multiparticle entanglement is important for entanglement theory as well as experimental studies related to quantum information theory. Here, we completely characterize genuine multiparticle entanglement for…

Quantum Physics · Physics 2011-11-28 Otfried Gühne , Bastian Jungnitsch , Tobias Moroder , Yaakov S. Weinstein

The first characterization of mixed-state entanglement was achieved for two-qubit states in Werner's seminal work [Phys. Rev. A 40, 4277 (1989)]. A physically important extension of this result concerns mixtures of a pure entangled state…

Quantum Physics · Physics 2015-06-15 Christopher Eltschka , Jens Siewert

We classify, up to local unitary equivalence, the set of $n$-qubit states that is stabilized by the diagonal subgroup of the local unitary group. We exhibit a basis for this set, parameterized by diagrams of nonintersecting chords…

Quantum Physics · Physics 2008-10-16 David W. Lyons , Scott N. Walck

The concept of entanglement and separability of quantum states is relevant for several fields in physics. Still, there is a lack of effective operational methods to characterise these features. We propose a method to certify quantum…

Quantum Physics · Physics 2024-03-06 Ties-A. Ohst , Xiao-Dong Yu , Otfried Gühne , H. Chau Nguyen

We generate and study the entanglement properties of novel states composed of three polarisation-encoded photonic qubits. By varying a single experimental parameter we can coherently move from a fully separable state to a maximally robust W…

Quantum Physics · Physics 2009-11-13 B. P. Lanyon , N. K. Langford

Entanglement lies at the heart of quantum information science, serving as a key resource for quantum communication, computation, and metrology. Consequently, high-precision entangled state preparation and efficient verification are…

We develop a method for visualizing the internal structure of multipartite entanglement in pure stabilizer states. Our algorithm graphically organizes the many-body correlations in a hierarchical structure. This provides a rich taxonomy…

Quantum Physics · Physics 2025-07-15 Vaibhav Sharma , Erich J Mueller

Many-body quantum systems can be characterised using the notions of \emph{k}-separability and entanglement depth. A quantum state is \emph{k}-separable if it can be expressed as a mixture of \emph{k} entangled subsystems, and its…

Experimental progress in qubit manufacturing calls for the development of new theoretical tools to analyze quantum data. We show how an unsupervised machine-learning technique can be used to understand short-range entangled many-qubit…

Quantum Physics · Physics 2023-03-22 Nicolas Sadoune , Giuliano Giudici , Ke Liu , Lode Pollet

We propose a scheme of multipartite entanglement distillation driven by a complementary pair of stabilizer measurements, to distill directly a wider range of states beyond the stabilizer code states (such as the Greenberger-Horne-Zeilinger…

Quantum Physics · Physics 2007-05-23 Akimasa Miyake , Hans J. Briegel

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

We report on the quantification of entanglement by means of entanglement measures on a four- and a six- qubit cluster state realized by using photons entangled both in polarization and linear momentum. This paper also addresss the question…

Quantum Physics · Physics 2011-03-23 H. Wunderlich , G. Vallone , P. Mataloni , M. B. Plenio

We theoretically investigate strategies for the deterministic creation of trains of time-bin entangled photons using an individual quantum emitter described by a $\Lambda$-type electronic system. We explicitly demonstrate the theoretical…

Quantum Physics · Physics 2024-11-27 David Bauch , Nikolas Köcher , Nils Heinisch , Stefan Schumacher

Cluster states are multi-particle entangled states with special entanglement properties particularly suitable for quantum computation. It has been shown that cluster states can exhibit Greenberger-Horne-Zeilinger (GHZ)-type non-locality…

Quantum Physics · Physics 2009-11-13 X. -Q. Zhou , C. -Y. Lu , W. -B. Gao , J. Zhang , Z. -B. Chen , T. Yang , J. -W. Pan

The determination of many special types of quantum states has been studied thoroughly, such as the generalized |GHZ> states, |W> states equivalent under stochastic local operations and classical communication and Dicke states. In this…

Quantum Physics · Physics 2015-07-08 Xia Wu , Ying-hui Yang , Yu-kun Wang , Qiao-yan Wen , Su-juan Qin , Fei Gao

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

Quantum state tomography, a process that reconstructs a quantum state from measurements on an ensemble of identically prepared copies, plays a crucial role in benchmarking quantum devices. However, brute-force approaches to quantum state…

Nonlocality is the defining feature of quantum entanglement. Entangled states with multiple particles are of crucial importance in fundamental tests of quantum physics as well as in many quantum information tasks. One of the archetypal…

Quantum Physics · Physics 2024-04-22 Leizhen Chen , Bochi Wu , Liangliang Lu , Kai Wang , Yanqing Lu , Shining Zhu , Xiao-Song Ma

Continuous-variable quantum states are of particular importance in various quantum information processing tasks including quantum communication and quantum sensing. However, a bottleneck has emerged with the fast increasing in size of the…

Quantum Physics · Physics 2021-10-13 Ye-Chao Liu , Jiangwei Shang , Xiangdong Zhang

Logic qubit entanglement, which is also called the concatenated Greenberger-Horne-Zeilinger (C-GHZ) state, is robust in practical noisy environment. In this paper, we will describe an efficient approach to realize the complete polarization…

Quantum Physics · Physics 2014-07-15 Yu-Bo Sheng , Lan Zhou