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

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Coupled cluster theory is one of the most accurate electronic structure methods for predicting ground and excited state chemistry. However, the presence of numerical artifacts at electronic degeneracies, such as complex energies, has made…

Chemical Physics · Physics 2024-05-16 Eirik F. Kjønstad , Sara Angelico , Henrik Koch

We combine the electron attachment (EA) and ionization potential (IP) equation-of-motion (EOM) coupled-cluster (CC) approaches with the CC($P$;$Q$) formalism. The resulting methodologies are used to describe the electronic states of several…

Chemical Physics · Physics 2025-09-19 Karthik Gururangan , Stephen H. Yuwono , A. Eugene DePrince , Piotr Piecuch

Molecular nanostructures are promising building blocks for future quantum technologies, provided methods of harnessing their multiple degrees of freedom can be identified and implemented. Due to low decoherence rates nuclear spins are…

Quantum Physics · Physics 2011-11-15 Marcus Schaffry , Brendon W. Lovett , Erik M. Gauger

Molecular spin clusters are mesoscopic systems whose structural and physical features can be tailored at the synthetic level. Besides, their quantum behavior is directly accessible in laboratory and their magnetic properties can be…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 F. Troiani , V. Bellini , A. Candini , G. Lorusso , M. Affronte

We propose how to generate genuine multipartite entanglement of electron spin qubits in a chain of quantum dots using the naturally available single-qubit rotations and two-qubit Heisenberg exchange interaction in the system. We show that…

Mesoscale and Nanoscale Physics · Physics 2007-11-14 F. Bodoky , M. Blaauboer

Coupled cluster theory in the standard formulation is unable to correctly describe conical intersections among states of the same symmetry. This limitation has restricted the practical application of an otherwise highly accurate electronic…

Chemical Physics · Physics 2024-12-25 Federico Rossi , Eirik F. Kjønstad , Sara Angelico , Henrik Koch

Adiabatic passage of two correlated electrons in three coupled quantum dots is shown to provide a robust and controlled way of distilling, transporting and detecting spin entanglement, as well as of measuring the rate of spin…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Jaroslav Fabian , Ulrich Hohenester

Frustrated spin models may lead to the formation of both classical non-collinear spin structures and unique quantum phases including highly entangled quantum spin liquids. Here, we study the entanglement and spatial quantum correlations in…

Strongly Correlated Electrons · Physics 2025-05-29 Levente Rózsa , Dennis Wuhrer , Sebastián A. Díaz , Ulrich Nowak , Wolfgang Belzig

We develop a new method to describe electromagnetic observables of open-shell nuclei with two nucleons outside a closed shell. This approach combines the equation-of-motion coupled-cluster method for such systems and the Lorentz integral…

Nuclear Theory · Physics 2024-10-14 Francesca Bonaiti , Sonia Bacca , Gaute Hagen , Gustav R. Jansen

We develop a new method to describe properties of truly open-shell nuclei. This method is based on single-reference coupled-cluster theory and the equation-of-motion method with extensions to nuclei with $A\pm 2$ nucleons outside a closed…

Nuclear Theory · Physics 2011-05-19 G. R. Jansen , M. Hjorth-Jensen , G. Hagen , T. Papenbrock

Using the approach to quantum entanglement based on the quantum fluctuations of observables, we show the existence of perfect entangled states of a single "spin-1" particle. We give physical examples related to the photons, condensed matter…

Quantum Physics · Physics 2007-05-23 M. Ali Can , Alexander Klyachko , Alexander Shumovsky

We introduce a shell-model theory that combines traditional spherical states, which yield a diagonal representation of the usual single-particle interaction, with collective configurations that track deformations, and test the validity of…

Nuclear Theory · Physics 2009-11-07 V. G. Gueorguiev , W. E. Ormand , C. W. Johnson , J. P. Draayer

We consider two quantum dots described by the Anderson-impurity model with one electron per dot. The goal of our work is to study the decay of a maximally entangled state between the two electrons localized in the dots. We prepare the…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 C. A. Büsser , I. de Vega , F. Heidrich-Meisner

Reduced-density-matrix-functional theory is applied to open-shell systems. We introduce a spin-restricted formulation by appropriately expressing approximate correlation-energy functionals in terms of spin-dependent occupation numbers and…

Strongly Correlated Electrons · Physics 2007-05-23 N. N. Lathiotakis , N. Helbig , E. K. U. Gross

We present an efficient entanglement concentration protocol (ECP) for mobile electrons with charge detection. This protocol is quite different from other ECPs for one can obtain a maximally entangled pair from a pair of less-entangled state…

Quantum Physics · Physics 2015-06-04 Yu-Bo Sheng , Lan Zhou , Wei-Wen Cheng , Long-Yan Gong , Sheng-Mei Zhao

Nuclear entanglement is a flagship in the interdisciplinary direction of nuclear physics and quantum information science. Spin entanglement, a special kind of nuclear entanglement, is ubiquitous in nuclear structures and dynamics. Based on…

Nuclear Theory · Physics 2024-03-08 Dong Bai

We present an approach to derive effective shell-model interactions from microscopic nuclear forces. The similarity-transformed coupled-cluster Hamiltonian decouples the single-reference state of a closed-shell nucleus and provides us with…

Nuclear Theory · Physics 2018-12-05 Z. H. Sun , T. D. Morris , G. Hagen , G. R. Jansen , T. Papenbrock

We describe a general technique that allows for an ideal transfer of quantum correlations between light fields and metastable states of matter. The technique is based on trapping quantum states of photons in coherently driven atomic media,…

Quantum Physics · Physics 2009-10-31 M. D. Lukin , S. F. Yelin , M. Fleischhauer

We simulate the coherence of two coupled electron spins interacting with a bath of nuclei using the generalized cluster correlation expansion (gCCE) method. An exchange interaction between the electrons facilitates a family of entangling…

Quantum Physics · Physics 2026-01-09 Xiao Chen , Silas Hoffman , James N. Fry , Hai-Ping Cheng

We extend coupled-cluster theory performed on top of a Slater determinant breaking rotational symmetry to allow for the exact restoration of the angular momentum at any truncation order. The main objective relates to the description of…

Nuclear Theory · Physics 2015-06-22 T. Duguet