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Related papers: The Complexity of Being Entangled

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We derive an explicit analytic estimate for the entanglement of a large class of bipartite quantum states which extends into bound entanglement regions. This is done by using an efficiently computable concurrence lower bound, which is…

Recently, an explicit relation between a measure of entanglement and a geometric entity has been reported in Quantum Inf. Process. (2016) 15:1629-1638. It has been shown that if a qubit gets entangled with another ancillary qubit then…

Quantum Physics · Physics 2019-04-10 Pratapaditya Bej , Prasenjit Deb

Topological quantum states cannot be created from product states with local quantum circuits of constant depth and are in this sense more entangled than topologically trivial states, but how entangled are they? Here we quantify the…

Quantum Physics · Physics 2015-05-27 Yichen Huang , Xie Chen

Grid states form a discrete set of mixed quantum states that can be described by graphs. We characterize the entanglement properties of these states and provide methods to evaluate entanglement criteria for grid states in a graphical way.…

Quantum Physics · Physics 2018-08-28 Joshua Lockhart , Otfried Gühne , Simone Severini

The computational complexity of a quantum state quantifies how hard it is to make. `Complexity geometry', first proposed by Nielsen, is an approach to defining computational complexity using the tools of differential geometry. Here we…

High Energy Physics - Theory · Physics 2021-04-01 Adam R. Brown , Leonard Susskind

Quantum entanglement, crucial for understanding quantum many-body systems and quantum gravity, is commonly assessed through various measures such as von Neumann entropy, mutual information, and entanglement contour, each with its inherent…

Quantum Physics · Physics 2025-07-08 Liang-Hong Mo , Yao Zhou , Jia-Rui Sun , Peng Ye

The preparation of $n$-qubit quantum states is a cross-cutting subroutine for many quantum algorithms, and the effort to reduce its circuit complexity is a significant challenge. In the literature, the quantum state preparation algorithm by…

Quantum Physics · Physics 2026-02-09 Giacomo Belli , Michele Amoretti

We consider a quantum many-body system made of $N$ interacting $S{=}1/2$ spins on a lattice, and develop a formalism which allows to extract, out of conventional magnetic observables, the quantum probabilities for any selected spin pair to…

Statistical Mechanics · Physics 2007-05-23 Andrea Fubini , Tommaso Roscilde , Valerio Tognetti , Matteo Tusa , Paola Verrucchi

Determining the quantum circuit complexity of a unitary operation is closely related to the problem of finding minimal length paths in a particular curved geometry [Nielsen et al, Science 311, 1133-1135 (2006)]. This paper investigates many…

Quantum Physics · Physics 2007-05-23 Mark R. Dowling , Michael A. Nielsen

We investigate the entanglement of the ground state in the quantum networks that their nodes are considered as quantum harmonic oscillators. To this aim, the Schmidt numbers and entanglement entropy between two arbitrary partitions of a…

Quantum Physics · Physics 2016-11-25 M. A. Jafarizadeh , S. Nami , F. Eghbalifam

We present a concise introduction to quantum entanglement. Concentrating on bipartite systems we review the separability criteria and measures of entanglement. We focus our attention on geometry of the sets of separable and maximally…

Quantum Physics · Physics 2007-05-23 Karol Zyczkowski , Ingemar Bengtsson

Entanglement, and quantum correlation, are precious resources for quantum technologies implementation based on quantum information science, such as, for instance, quantum communication, quantum computing, and quantum interferometry.…

Quantum Physics · Physics 2023-05-22 Arthur Vesperini , Ghofrane Bel-Hadj-Aissa , Roberto Franzosi

Considering pure quantum states, entanglement concentration is the procedure where from $N$ copies of a partially entangled state, a single state with higher entanglement can be obtained. Getting a maximally entangled state is possible for…

Quantum Physics · Physics 2023-04-12 L. Palma Torres , M. A. Solís-Prosser , O. Jiménez , E. S. Gómez , A. Delgado

An entanglement measure for a bipartite quantum system is a state functional that vanishes on separable states and that does not increase under separable (local) operations. It is well-known that for pure states, essentially all…

Quantum Physics · Physics 2025-08-22 Stefan Hollands , Ko Sanders

The correspondence principle plays a fundamental role in quantum mechanics, which naturally leads us to inquire whether it is possible to find or determine close classical analogs of quantum states in phase space -- a common meeting point…

Quantum Physics · Physics 2022-01-28 A. S. Sanz

A deep understanding of quantum entanglement is vital for advancing quantum technologies. The strength of entanglement can be quantified by counting the degrees of freedom that are entangled, which results in a quantity called Schmidt…

Quantum Physics · Physics 2024-02-21 Robin Krebs , Mariami Gachechiladze

As a new step towards defining complexity for quantum field theories, we map Nielsen operator complexity for $SU(N)$ gates to two-dimensional hydrodynamics. We develop a tractable large $N$ limit that leads to regular geometries on the…

High Energy Physics - Theory · Physics 2022-10-05 Pablo Basteiro , Johanna Erdmenger , Pascal Fries , Florian Goth , Ioannis Matthaiakakis , René Meyer

In this paper, we construct 2-dimensional bipartite cluster states and perform single-qubit measurements on the bulk qubits. We explore the entanglement scaling of the unmeasured 1-dimensional boundary state and show that under certain…

Quantum Physics · Physics 2025-01-29 Hanchen Liu , Vikram Ravindranath , Xiao Chen

Quantum entanglement is an essential resource for quantum science and technology. However, entanglement detection and quantification, via typical entanglement measures such as linear entanglement entropy or negativity, can be a very…

Quantum Physics · Physics 2025-06-17 Diego Fallas Padilla , Mingjian Zhu , Han Pu

We investigate bipartite entanglement in spin-1/2 systems on a generic lattice. For states that are an equal superposition of elements of a group $G$ of spin flips acting on the fully polarized state $\ket{0}^{\otimes n}$, we find that the…

Quantum Physics · Physics 2007-05-23 Alioscia Hamma , Radu Ionicioiu , Paolo Zanardi