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We propose three criteria for identifying continuous variable entanglement between two many-particle systems with no restrictions on the quantum state of the local oscillators used in the measurements. Mistakenly asserting a coherent state…

Quantum Physics · Physics 2009-11-13 A. J. Ferris , M. K. Olsen , E. G. Cavalcanti , M. J. Davis

A simple model coupling a one-dimensional beam particle to a one-dimensional harmonic oscillator is used to explore complementarity and entanglement. This model, well-known in the inelastic scattering literature, is presented under three…

Quantum Physics · Physics 2023-09-26 David Kordahl

We introduce a quantum information analysis of vibrational wave functions to understand complex vibrational spectra of molecules with strong anharmonic couplings and vibrational resonances. For this purpose, we define one- and two-modal…

Chemical Physics · Physics 2024-07-12 Nina Glaser , Alberto Baiardi , Annina Z. Lieberherr , Markus Reiher

We present in detail a statistical approach for the reference-frame-independent detection and characterization of multipartite entanglement based on moments of randomly measured correlation functions. We start by discussing how the…

Quantum Physics · Physics 2020-09-23 Andreas Ketterer , Nikolai Wyderka , Otfried Gühne

Entanglement is a key ingredient for quantum technologies and a fundamental signature of quantumness in a broad range of phenomena encompassing many-body physics, thermodynamics, cosmology, and life sciences. For arbitrary multiparticle…

Quantum Physics · Physics 2016-10-24 Marco Cianciaruso , Thomas R. Bromley , Gerardo Adesso

We consider information spreading measures in randomly initialized variational quantum circuits and introduce entanglement diagnostics for efficient variational quantum/classical computations. We establish a robust connection between…

Quantum Physics · Physics 2022-07-27 Joonho Kim , Yaron Oz

Quantifying correlation and entanglement between molecular orbitals can elucidate the role of quantum effects in strongly correlated reaction processes. However, accurately storing the wavefunction for a classical computation of those…

Entanglement is the crucial ingredient of quantum many-body physics, and characterizing and quantifying entanglement in closed system dynamics of quantum simulators is an outstanding challenge in today's era of intermediate scale quantum…

Quantum Physics · Physics 2021-08-31 Christian Kokail , Rick van Bijnen , Andreas Elben , Benoît Vermersch , Peter Zoller

We show that the general Heisenberg Hamiltonian with non-uniform couplings can be characterised by mapping the entanglement it generates as a function of time. Identification of the Hamiltonian in this way is possible as the coefficients of…

Quantum Physics · Physics 2007-05-23 Jared H. Cole , Simon J. Devitt , Lloyd C. L. Hollenberg

Quantum entanglement has been identified as a crucial concept underlying many intriguing phenomena in condensed matter systems, such as topological phases or many-body localization. Recently, instead of considering mere quantifiers of…

Quantum Physics · Physics 2024-02-12 Niklas Euler , Martin Gärttner

We present a theoretical study of entanglement in ensembles consisting of an arbitrary number of particles. Multipartite entanglement criteria in terms of observables are formulated for a fixed number of particles as well as for systems…

Quantum Physics · Physics 2017-06-22 J. Sperling , I. A. Walmsley

Multi-configurational approaches yield universal wave function parameterizations that can qualitatively well describe electronic structures along reaction pathways. For quantitative results, multi-reference perturbation theory is required…

Chemical Physics · Physics 2016-09-08 Christopher J. Stein , Vera von Burg , Markus Reiher

Multipartite entanglement detection is crucial for the develop of quantum information science and quantum computation, communication, simulation and metrology tasks. In contrast to experiments, where several handreds of qubits have been…

Quantum Physics · Physics 2024-11-06 Xiao-yu Chen

The quantum mechanical description of the chemical bond is generally given in terms of delocalized bonding orbitals, or, alternatively, in terms of correlations of occupations of localised orbitals. However, in the latter case, multiorbital…

Quantum Physics · Physics 2017-05-23 Szilárd Szalay , Gergely Barcza , Tibor Szilvási , Libor Veis , Örs Legeza

We develop an extension of the Monte Carlo wave function approach that unambiguously identifies dynamical entanglement in general composite, open systems. Our algorithm performs tangential projections onto the set of separable states,…

Quantum Physics · Physics 2026-01-21 Laura Ares , Julien Pinske , Benjamin Hinrichs , Martin Kolb , Jan Sperling

Quantum entanglement is commonly assumed to be a central resource for quantum computing and quantum simulation. Nonetheless, the capability to detect it in many-body systems is severely limited by the absence of sufficiently scalable and…

Quantum Physics · Physics 2022-03-17 Irénée Frérot , Flavio Baccari , Antonio Acín

The coupling of a qubit to a macroscopic reservoir plays a fundamental role in understanding the complex transition from the quantum to the classical world. Considering a harmonic environment, we use both intuitive arguments and numerical…

Mesoscale and Nanoscale Physics · Physics 2013-02-01 Soumya Bera , Serge Florens , Harold Baranger , Nicolas Roch , Ahsan Nazir , Alex Chin

We present a unified framework for multipartite entanglement characterization based on the conditional gradient (CG) method, incorporating both fast heuristic detection and rigorous witness construction with numerical error control. Our…

Quantum Physics · Physics 2025-08-04 Ye-Chao Liu , Jannis Halbey , Sebastian Pokutta , Sébastien Designolle

Entanglement plays a central role in quantum technologies, yet its characterization and control in materials remain challenging. Recent developments in spectrum-based entanglement witnesses have enabled new strategies for quantifying…

Quantum Physics · Physics 2025-12-09 Zecheng Shen , Shuhan Ding , Zijun Zhao , Francesco A. Evangelista , Yao Wang

We present an approach to characterize genuine multiparticle entanglement using appropriate approximations in the space of quantum states. This leads to a criterion for entanglement which can easily be calculated using semidefinite…

Quantum Physics · Physics 2011-05-13 Bastian Jungnitsch , Tobias Moroder , Otfried Gühne