English
Related papers

Related papers: Twin GHZ-states behave differently

200 papers

Graph states are an important class of multipartite entangled states. Previous experimental generation of graph states and in particular the Greenberger-Horne-Zeilinger (GHZ) states in linear optics quantum information schemes is subjected…

Quantum Physics · Physics 2022-03-01 Sheng Zhang , Yu-Kai Wu , Chang Li , Nan Jiang , Yun-Fei Pu , Lu-Ming Duan

We generalize Greenberger-Horne-Zeilinger (GHZ) nonlocality to every even-dimensional and odd-partite system. For the purpose we employ concurrent observables that are incompatible and nevertheless have a common eigenstate. It is remarkable…

Quantum Physics · Physics 2007-05-23 Jinhyoung Lee , Seung-Woo Lee , M. S. Kim

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 present an efficient method to generate a Greenberger-Horne-Zeilinger (GHZ) entangled state of three cat-state qubits (cqubits) via circuit QED. The GHZ state is prepared with three microwave cavities coupled to a superconducting…

Quantum Physics · Physics 2019-10-23 Chui-Ping Yang , Zhen-Fei Zheng

Entanglement is the quintessential quantum phenomenon and a key enabler of quantum algorithms. The ability to faithfully entangle many distinct particles is often used as a benchmark for the quality of hardware and control in a quantum…

Quantum Physics · Physics 2025-10-13 Ali Javadi-Abhari , Simon Martiel , Alireza Seif , Maika Takita , Ken X. Wei

Photonic GHZ states serve as the central resource for a number of important applications in quantum information science, including secret sharing, sensing, and fusion-based quantum computing. The use of photon-emitter entangling gates is a…

Quantum Physics · Physics 2025-10-02 Rafail Frantzeskakis , Chenxu Liu , Zahra Raissi , Edwin Barnes , Sophia E. Economou

The states in the three-qubit GHZ SLOCC class can exhibit diverse entanglement patterns, as they may have no entanglement in any reduced subsystems, or show entanglement across one, two, or all three bipartite cuts. Significant research has…

Tripartite entangled states, such as GHZ and W states, are typically generated by manipulating two pairs of polarization-entangled photons in bulk optics. Here we propose a scheme to generate W states that are entangled in the energy degree…

Quantum Physics · Physics 2016-08-03 M. Menotti , L. Maccone , J. E. Sipe , M. Liscidini

Quantum entanglement involving coherent superpositions of macroscopically distinct states is among the most striking features of quantum theory, but its realization is challenging, since such states are extremely fragile. Using a…

Optically-controlled exciton dynamics in coupled quantum dots is studied. We show that the maximally entangled Bell states and Greenberger-Horne-Zeilinger (GHZ) states can be robustly generated by manipulating the system parameters to be at…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Ping Zhang , C. K. Chan , Qi-Kun Xue , Xian-Geng Zhao

Systems of four nonbinary particles, each having three or more internal states, exhibit maximally entangled states that are inaccessible to four qubits. This breaks the pattern of two- and three-particle systems, in which the existing graph…

Quantum Physics · Physics 2015-06-23 Mario Gaeta , Andrei Klimov , Jay Lawrence

We present a broad class of states which are diagonal in the basis of N-qubit GHZ states such that non-positivity under the partial transpose operation is necessary and sufficient for the presence of entanglement. This class includes many…

Quantum Physics · Physics 2011-02-23 Alastair Kay

We introduce two operational entanglement measures which are applicable for arbitrary multipartite (pure or mixed) states. One of them characterizes the potentiality of a state to generate other states via local operations assisted by…

Quantum Physics · Physics 2015-10-14 K. Schwaiger , D. Sauerwein , M. Cuquet , J. I. de Vicente , B. Kraus

We characterize entanglement subject to its definition over real and complex, composite quantum systems. In particular, a method is established to assess quantum correlations with respect to a selected number system, illuminating the deeply…

How entangled is a randomly chosen bipartite stabilizer state? We show that if the number of qubits each party holds is large the state will be close to maximally entangled with probability exponentially close to one. We provide a similar…

Quantum Physics · Physics 2007-05-23 Graeme Smith , Debbie Leung

In addition to being a workhorse for modern quantum technologies, entanglement plays a key role in fundamental tests of quantum mechanics. The entanglement of photons in multiple levels, or dimensions, explores the limits of how large an…

Quantum Physics · Physics 2018-03-12 Manuel Erhard , Mehul Malik , Anton Zeilinger

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…

Multi-photon entanglement plays a central role in optical quantum technologies. One way to entangle two photons is to prepare them in orthogonal internal states, for example, in two polarisations, and then send them through a balanced beam…

Quantum Physics · Physics 2023-09-06 Shreya Kumar , Daniel Bhatti , Alex E. Jones , Stefanie Barz

Fault-tolerant quantum computation can be achieved by creating constant-sized, entangled resource states and performing entangling measurements on subsets of their qubits. Linear optical quantum computers can be designed based on this…

Quantum Physics · Physics 2026-02-03 Brendan Pankovich , Alex Neville , Angus Kan , Srikrishna Omkar , Kwok Ho Wan , Kamil Brádler

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