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The diagram technique for the one-band Hubbard model is formulated for the case of moderate to strong Hubbard repulsion. The expansion in powers of the hopping constant is expressed in terms of site cumulants of electron creation and…

Strongly Correlated Electrons · Physics 2009-11-11 A. Sherman

We review a recent approach for the simulation of many-body interacting systems based on an efficient generalization of the Lanczos method for Quantum Monte Carlo simulations. This technique allows to perform systematic corrections to a…

Strongly Correlated Electrons · Physics 2007-05-23 Sandro Sorella

A method to calculate the one-body Green's function for ground states of correlated electron materials is formulated by extending the variational Monte Carlo method. We benchmark against the exact diagonalization (ED) for the one- and…

Strongly Correlated Electrons · Physics 2020-11-11 Maxime Charlebois , Masatoshi Imada

The famous, yet unsolved, Fermi-Hubbard model for strongly-correlated electronic systems is a prominent target for quantum computers. However, accurately representing the Fermi-Hubbard ground state for large instances may be beyond the…

The problem of optimising functions with intractable gradients frequently arise in machine learning and statistics, ranging from maximum marginal likelihood estimation procedures to fine-tuning of generative models. Stochastic approximation…

Machine Learning · Statistics 2026-01-30 James Cuin , Davide Carbone , Yanbo Tang , O. Deniz Akyildiz

Variational inference approximates the posterior distribution of a probabilistic model with a parameterized density by maximizing a lower bound for the model evidence. Modern solutions fit a flexible approximation with stochastic gradient…

Machine Learning · Statistics 2017-07-13 Joseph Sakaya , Arto Klami

In this tutorial presentation, we give a comprehensive introduction into the Gutzwiller variational approach and its merger with the density functional theory. The merits of this method are illustrated by a discussion of results for…

Strongly Correlated Electrons · Physics 2012-07-30 Jörg Bünemann

The two-dimensional Hubbard model is analyzed in the framework of the two-pole expansion. It is demonstrated that several theoretical approaches, when considered at their lowest level, are all equivalent and share the property of satisfying…

Strongly Correlated Electrons · Physics 2008-02-03 A. Avella , F. Mancini , D. Villani , L. Siurakshina , V. Yu. Yushankhai

We use a variational Monte Carlo algorithm to solve the electronic structure of two-dimensional semiconductor quantum dots in external magnetic field. We present accurate many-body wave functions for the system in various magnetic field…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Ari Harju

We investigate the applicability of the two existing versions of a time-dependent Gutzwiller approximation (TDGA) beyond the frequently used limit of infinite spatial dimensions. To this end, we study the two-particle response functions of…

Strongly Correlated Electrons · Physics 2016-02-22 J. Bünemann , S. Wasner , E. v. Oelsen , G. Seibold

Variational wave function ansatze are an invaluable tool to study the properties of strongly correlated systems. We propose such a wave function, based on the theory of auxiliary fields and combining aspects of auxiliary-field quantum Monte…

Strongly Correlated Electrons · Physics 2024-03-13 Ryan Levy , Miguel A. Morales , Shiwei Zhang

An extension to the multiple-histogram method (sometimes referred to as the Ferrenberg-Swendsen method) for use in quantum Monte Carlo simulations is presented. This method is shown to work well for the 2D repulsive Hubbard model, allowing…

Strongly Correlated Electrons · Physics 2009-10-31 Christopher L. Martin

We investigate an extended version of the periodic Anderson model (the so-called periodic Anderson-Hubbard model) with the aim to understand the role of interaction between conduction electrons in the formation of the heavy-fermion and…

Strongly Correlated Electrons · Physics 2013-05-30 I. Hagymasi , K. Itai , J. Solyom

We present a self-consistent numerical approach to solve the Gutzwiller variational problem for general multi-band models with arbitrary on-site interaction. The proposed method generalizes and improves the procedure derived by Deng et al.,…

Strongly Correlated Electrons · Physics 2015-05-30 Nicola Lanatà , Hugo U. R. Strand , Xi Dai , Bo Hellsing

We consider an effective Hubbard model with spin- and direction-dependent complex hoppings $t$, applied to twisted homobilayer WSe$_2$ using a variational Monte Carlo approach. The electronic correlations are taken into account by applying…

Strongly Correlated Electrons · Physics 2024-01-10 Andrzej Biborski , Paweł Wójcik , Michał Zegrodnik

In this paper we compare numerical results for the ground state of the Hubbard model obtained by Quantum-Monte-Carlo simulations with results from exact and stochastic diagonalizations. We find good agreement for the ground state energy and…

Condensed Matter · Physics 2015-06-25 Thomas Husslein , Werner Fettes , Ingo Morgenstern

We propose sequential Monte Carlo based algorithms for maximum likelihood estimation of the static parameters in hidden Markov models with an intractable likelihood using ideas from approximate Bayesian computation. The static parameter…

Computation · Statistics 2013-11-19 Sinan Yildirim , Sumeetpal Singh , Thomas Dean , Ajay Jasra

We report multipronged progress on the stochastic averaging approach to numerical analytic continuation of quantum Monte Carlo data. With the sampled spectrum parametrized with delta-functions in continuous frequency space, a calculation of…

Strongly Correlated Electrons · Physics 2023-01-11 Hui Shao , Anders W. Sandvik

We design a quantum molecular dynamics method for strongly correlated electron metals. The strong electronic correlation effects are treated within a real-space version of the Gutzwiller variational approximation (GA), which is suitable for…

Strongly Correlated Electrons · Physics 2017-07-12 Jean-Pierre Julien , Joel D. Kress , Jian-Xin Zhu

An investigation is presented of the utility of semiclassical approximations for solving the quantum-impurity problems arising in the dynamical-mean-field approach to the correlated-electron models. The method is based on performing a exact…

Strongly Correlated Electrons · Physics 2009-11-11 Satoshi Okamoto , Andreas Fuhrmann , Armin Comanac , Andrew J. Millis
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