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Related papers: Entanglement Coupled Cluster Theory: Exact Spin-Ad…

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Spin correlations are carefully investigated in elastic $e^{+}e^{-}$ scattering in QED, for initially \textit{polarized} as well as \textit{unpolarized} particles, with emphasis placed on energy or speed of the underlying particles involved…

Quantum Physics · Physics 2008-07-14 Nattapong Yongram

We develop a coupled-cluster theory for bosonic mixtures of binary species in external traps, providing a promising theoretical approach to demonstrate highly accurately the many-body physics of mixtures of Bose-Einstein condensates. The…

Quantum Gases · Physics 2024-02-01 Anal Bhowmik , Ofir E. Alon

The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which…

Chemical Physics · Physics 2016-02-25 Thomas M. Henderson , Ireneusz W. Bulik , Gustavo E. Scuseria

We present a practical approach to treat static and dynamical correlation accurately in large multi-configurational systems. The static correlation is accounted for using the spin-flip approach which is well known for capturing static…

Strongly Correlated Electrons · Physics 2021-02-08 Oinam Romesh Meitei , Nicholas J. Mayhall

Entanglement is a fundamental property of quantum systems, essential for non-trivial quantum programs. Identifying when qubits become entangled is critical for circuit optimization, and for arguing for the correctness of quantum algorithms.…

Quantum Physics · Physics 2025-08-15 Aske Nord Raahauge , Martin Bom Marchioro , Rasmus Ross Nylandsted

We present several coupled-cluster calculations of ground and excited states of 4He and 16O employing methods from quantum chemistry. A comparison of coupled cluster results with the results of exact diagonalization of the hamiltonian in…

Multicomponent systems are defined as chemical systems that require a quantum mechanical description of two or more different types of particles. Non-Born-Oppenheimer electron-nuclear interactions in molecules, electron-hole interactions in…

Chemical Physics · Physics 2015-10-21 Benjamin H. Ellis , Somil Aggarwal , Arindam Chakraborty

The spin-boson model, involving spins interacting with a bath of quantum harmonic oscillators, is a widely used representation of open quantum systems. Trapped ions present a natural platform for simulating the quantum dynamics of such…

This paper explores the connections between particle scattering and quantum information theory in the context of the non-relativistic, elastic scattering of two spin-1/2 particles. An untangled, pure, two-particle in-state is evolved by an…

Quantum Physics · Physics 2009-11-11 N. L. Harshman

Molecular orbital theory is powerful both as a conceptual tool for understanding chemical bonding, and as a theoretical framework for ab initio quantum chemistry. Despite its undoubted success, MO theory has well documented shortcomings,…

Chemical Physics · Physics 2024-02-15 Daniel Marti-Dafcik , Nicholas Lee , Hugh G. A. Burton , David P. Tew

Entangled solitons construction being introduced in the nonlinear spinor field model, the Einstein|Podolsky|Rosen (EPR) spin correlation is calculated and shown to coincide with the quantum mechanical one for the 1/2-spin particles.

Quantum Physics · Physics 2021-09-21 Yu. P. Rybakov , T. F. Kamalov

We investigate quantum dynamics in the electron-nuclei coupled spin system in quantum dots and clarify the fundamental features of quantum correlation induced via successive electron spin measurements. This quantum correlation leads to…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Ozgur Cakir , Toshihide Takagahara

Quantum mechanics exhibits a wide range of nonclassical features, of which entanglement in multipartite systems takes a central place. In several specific settings, it is well known that nonclassicality (e.g., squeezing, spin squeezing,…

Quantum Physics · Physics 2016-02-25 Nathan Killoran , Frank E. S. Steinhoff , Martin B. Plenio

In this work we develop a theory of correlated many-electron dynamics dressed by the presence of a finite-temperature harmonic bath. The theory is based on the ab-initio Hamiltonian, and thus well-defined apart from any phenomenological…

Quantum Physics · Physics 2015-06-05 John A. Parkhill , Thomas Markovich , David G. Tempel , Alan Aspuru-Guzik

We introduce a simple, experimentally realisable, entanglement manipulation protocol for exploring mixed state entanglement. We show that for both non-maximally entangled pure, and mixed polarisation-entangled two qubit states, an increase…

Quantum Physics · Physics 2009-11-06 R. T. Thew , W. J. Munro

The coupling between the states of a system and the continuum into which it is embedded, induces correlations that are especially large in the short time scale. These correlations cannot be calculated by using a statistical or…

Nuclear Theory · Physics 2007-05-23 J. Okołowicz , M. Płoszajczak , I. Rotter

Without resorting to spin-spin coupling, we propose a scalable spin quantum computing scheme assisted with a semiconductor multiple-quantum-dot structure. The techniques of single electron transitions and the nanostructure of quantum-dot…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Wei-Min Zhang , Yin-Zhong Wu , Chopin Soo , Mang Feng

A general-order open-shell coupled-cluster method based on spatial orbitals is formulated. The method is an extension of the partial-spin adaptation (PSA) scheme from Janssen and Schaefer (Theor. Chim. Acta, 79, 1-42, 1991). By increasing…

Chemical Physics · Physics 2024-03-18 Cong Wang

Cluster dynamics and single-particle correlation are simultaneously treated for the description of the ground state of ${}^{12} \mathrm{C} $. The recent development of the antisymmetrized quasi cluster model (AQCM) makes it possible to…

Nuclear Theory · Physics 2021-04-06 Naoyuki Itagaki , Tomoya Naito

The theory of correlated electron systems is formulated in a form which allows to use as a reference point an ab initio band structure theory (AIBST). The theory is constructed in two steps. As a first step the total Hamiltonian is…

Strongly Correlated Electrons · Physics 2007-05-23 Igor Sandalov , Borje Johansson , Olle Eriksson