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We propose a data-driven approach using a Restricted Boltzmann Machine (RBM) to solve the Schr\"odinger equation in configuration space. Traditional Configuration Interaction (CI) methods construct the wavefunction as a linear combination…

We study the quantum version of a simplified model of optimization problems, where quantum fluctuations are introduced by a transverse field acting on the qubits. We find a complex low-energy spectrum of the quantum Hamiltonian,…

Statistical Mechanics · Physics 2010-10-13 Laura Foini , Guilhem Semerjian , Francesco Zamponi

The electronic and emission properties of correlated multi-particle states are studied theoretically using ${\bf k}\cdot{\bf p}$ and the configuration interaction methods on a well-known and measured GaAs/AlGaAs quantum dots as a test…

Mesoscale and Nanoscale Physics · Physics 2025-04-15 Petr Klenovsky

For a given many-electron molecule, it is possible to define a corresponding one-electron Schr\"odinger equation, using potentials derived from simple atomic densities, whose solution predicts fairly accurate molecular orbitals for single-…

Chemical Physics · Physics 2022-05-16 Jerry L. Whitten

High-order perturbative $\textit{ab initio}$ calculations are challenging due to the rapidly growing configuration space and the difficulty of assessing convergence. In this letter, we introduce perturbation theory quantum Monte Carlo…

Nuclear Theory · Physics 2026-05-06 Xin Zhen , Rongzhe Hu , Junchen Pei , Furong Xu

We consider two weakly coupled systems and adopt a perturbative approach based on the Ruelle response theory to study their interaction. We propose a systematic way to parametrize the effect of the coupling as a function of only the…

Statistical Mechanics · Physics 2012-08-16 Jeroen Wouters , Valerio Lucarini

Measuring the expectation value of the molecular electronic Hamiltonian is one of the challenging parts of the variational quantum eigensolver. A widely used strategy is to express the Hamiltonian as a sum of measurable fragments using…

Quantum Physics · Physics 2023-01-04 Seonghoon Choi , Ignacio Loaiza , Artur F. Izmaylov

The dynamics of the nuclear-spin quantum computer with large number (L=1000) of qubits is considered using a perturbation approach, based on approximate diagonalization of exponentially large sparse matrices. Small parameters are introduced…

Quantum Physics · Physics 2007-05-23 G. P. Berman , D. I. Kamenev , V. I. Tsifrinovich

We develop several configuration interaction approaches for characterizing the electronic structure of an adsorbate on a metal surface (at least in model form). When one can separate adsorbate from substrate, these methods can achieve a…

Chemical Physics · Physics 2020-02-26 Zuxin Jin , Wenjie Dou , Joseph E. Subotnik

The strong-coupling perturbation theory (SCPT) for correlated electron systems is extended to the case of full Coulomb interaction. The Coulomb mechanism of the orbital polarization is discussed and attention is paid to the importance of…

Strongly Correlated Electrons · Physics 2007-05-23 I. Sandalov , U. Lundin , O. Eriksson

The paper examines a trapped one-dimensional system of multicomponent spinless fermions that interact with a zero-range two-body potential. We show that when the repulsion between particles is very large the system can be approached…

An accurate description of nonadiabatic dynamics of molecular species on metallic surfaces poses a serious computational challenge associated with a multitude of closely-spaced electronic states. We propose a mixed quantum-classical scheme…

Chemical Physics · Physics 2017-01-10 Ilya G. Ryabinkin , Artur F. Izmaylov

Following Ref. [Oriols X 2007 Phys. Rev. Lett., 98 066803], an algorithm to deal with the exchange interaction in non-separable quantum systems is presented. The algorithm can be applied to fermions or bosons and, by construction, it…

Quantum Physics · Physics 2014-08-05 A. Alarcón , S. Yaro , X. Cartoixà , X. Oriols

Effective interactions inherently encompass many-body effects that appear unified. Analyzing these in reverse, that is, separating them into contributions from pairs, triples, or larger groups, is typically intricate and seldom pursued.…

For a given many-electron molecule, it is possible to define a corresponding one-electron Schr\"odinger equation, using potentials derived from simple atomic densities, whose solution predicts fairly accurate molecular orbitals for single-…

Chemical Physics · Physics 2022-05-16 Fariba Nazari , Jerry L. Whitten

After a sudden disruption, weakly interacting quantum systems first relax to a prethermalized state that can be described by perturbation theory and a generalized Gibbs ensemble. Using these properties of the prethermalized state we…

Strongly Correlated Electrons · Physics 2013-08-27 Michael Stark , Marcus Kollar

Collective phenomena in strongly nonequilibrium systems interacting with electromagnetic field are considered. Such systems are described by complicated nonlinear differential or integro-differential equations. The aim of this review is to…

Condensed Matter · Physics 2007-05-23 V. I. Yukalov , E. P. Yukalova

Starting from the full many-body Hamiltonian of interacting electrons the effective self-energy acting on electrons residing in a subspace of the full Hilbert space is derived. This subspace may correspond to, for example, partially filled…

Strongly Correlated Electrons · Physics 2010-10-20 F. Aryasetiawan , J. M. Tomczak , T. Miyake , R. Sakuma

The efficiency of the variational perturbation theory [Phys. Rev. C {\bf 62}, 045503 (2000)] formulated recently for many-particle systems is examined by calculating the ground state correlation energy of the 3D electron gas with the…

Strongly Correlated Electrons · Physics 2009-11-07 Sang Koo You , Noboru Fukushima

Typically in many-body systems the correlation energy, which is defined as the difference between the exact ground state energy and the mean-field solution, has been a measure of the system's total correlations. However, under the quantum…

Quantum Physics · Physics 2021-10-04 Javier Faba , Vicente Martín , Luis Robledo