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Explicit treatment of many-body Fermi statistics in path integral Monte Carlo (PIMC) results in exponentially scaling computational cost due to the near cancellation of contributions to observables from even and odd permutations. Through…

Strongly Correlated Electrons · Physics 2014-09-12 Jonathan L DuBois , Ethan W. Brown , Berni J. Alder

The `dynamic' Hubbard Hamiltonian describes interacting fermions on a lattice whose on-site repulsion is modulated by a coupling to a fluctuating bosonic field. We investigate one such model, introduced by Hirsch, using the determinant…

Superconductivity · Physics 2009-11-13 K. Bouadim , M. Enjalran , F. Hebert , G. G. Batrouni , R. T. Scalettar

Recently developed neural network-based \emph{ab-initio} solutions (Pfau et. al arxiv:1909.02487v2) for finding ground states of fermionic systems can generate state-of-the-art results on a broad class of systems. In this work, we improve…

Chemical Physics · Physics 2021-03-26 Max Wilson , Nicholas Gao , Filip Wudarski , Eleanor Rieffel , Norm M. Tubman

A new Markov Chain Monte Carlo method for simulating the dynamics of molecular systems characterized by hard-core interactions is introduced. In contrast to traditional Kinetic Monte Carlo approaches, where the state of the system is…

Computational Physics · Physics 2017-02-07 Liborio I. Costa

A new class of the constrained Monte Carlo (CMC) algorithms for the QCD evolution equation was recently discovered. The constraint is imposed on the type and the total longitudinal energy of the parton exiting QCD evolution and entering a…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Jadach , M. Skrzypek

Sign problem in quantum Monte Carlo (QMC) simulation appears to be an extremely hard yet interesting problem. In this article, we present a pedagogical overview on the origin of the sign problem in various quantum Monte Carlo simulation…

Strongly Correlated Electrons · Physics 2023-10-27 Gaopei Pan , Zi Yang Meng

Simulating models for quantum correlated matter unveils the inherent limitations of deterministic classical computations. In particular, in the case of quantum Monte Carlo methods, this is manifested by the emergence of negative weight…

Strongly Correlated Electrons · Physics 2022-11-23 Tian-Cheng Yi , Richard T. Scalettar , Rubem Mondaini

We describe computational methods for the theoretical study of explicit correlations beyond the mean field in excitons confined in semiconductor quantum dots in terms of the Auxiliary-Field Monte Carlo (AFMC) method. Using AFMC, the…

Strongly Correlated Electrons · Physics 2009-09-25 D. J. Dean , M. R. Strayer , J. C. Wells

We present a novel quasi-Monte Carlo mechanism to improve graph-based sampling, coined repelling random walks. By inducing correlations between the trajectories of an interacting ensemble such that their marginal transition probabilities…

Machine Learning · Statistics 2024-05-27 Isaac Reid , Eli Berger , Krzysztof Choromanski , Adrian Weller

The quantum Monte Carlo algorithm is arguably one of the most powerful computational many-body methods, enabling accurate calculation of many properties in interacting quantum systems. In the presence of the so-called sign problem, the…

Strongly Correlated Electrons · Physics 2018-02-23 Chia-Chen Chang , Miguel A. Morales

The time dependent quantum Monte Carlo method for fermions is introduced and applied for calculation of entanglement of electrons in one-dimensional quantum dots with several spin-polarized and spin-compensated electron configurations. The…

Quantum Physics · Physics 2021-07-09 Ivan P. Christov

We present a general technique for addressing sign problems that arise in Monte Carlo simulations of field theories. This method deforms the domain of the path integral to a manifold in complex field space that maximizes the average sign…

High Energy Physics - Lattice · Physics 2018-06-06 Andrei Alexandru , Paulo Bedaque , Henry Lamm , Scott Lawrence

Path integral Monte Carlo (PIMC) simulations have become an important tool for the investigation of the statistical mechanics of quantum systems. I discuss some of the history of applying the Monte Carlo method to non-relativistic quantum…

History and Philosophy of Physics · Physics 2016-11-23 Tilman Sauer

The effectiveness of the recently developed Fixed-Node Quantum Monte Carlo method for lattice fermions, developed by van Leeuwen and co-workers, is tested by applying it to the 1D Kondo lattice, an example of a one-dimensional model with a…

Condensed Matter · Physics 2007-05-23 H. J. M. van Bemmel , W. van Saarloos , D. F. B. ten Haaf

Hamiltonian Monte Carlo (HMC) algorithms which combine numerical approximation of Hamiltonian dynamics on finite intervals with stochastic refreshment and Metropolis correction are popular sampling schemes, but it is known that they may…

Computation · Statistics 2022-08-16 Peter A. Whalley , Daniel Paulin , Benedict Leimkuhler

As an intrinsically-unbiased approach, quantum Monte Carlo (QMC) is of vital importance in understanding correlated phases of matter. Unfortunately, it often suffers notorious sign problem when simulating interacting fermion models. Here,…

Strongly Correlated Electrons · Physics 2022-11-03 Zi-Xiang Li , Zhou-Quan Wan , Hong Yao

The notorious fermion sign problem, arising from fermion statistics, presents a fundamental obstacle to the numerical simulation of quantum many-body systems. Here, we introduce a framework that circumvents the sign problem in the studies…

Strongly Correlated Electrons · Physics 2026-01-07 Yin-Kai Yu , Zhi-Xuan Li , Shuai Yin , Zi-Xiang Li

We introduce a method that combines the power of both the lattice Green function Monte Carlo (LGFMC) with the auxiliary field techniques (AFQMC), and allows us to compute exact ground state properties of the Hubbard model for U<~ 4t on…

Strongly Correlated Electrons · Physics 2015-06-03 Sandro Sorella

The ab initio thermodynamic simulation of correlated Fermi systems is of central importance for many applications, such as warm dense matter, electrons in quantum dots, and ultracold atoms. Unfortunately, path integral Monte Carlo (PIMC)…

Computational Physics · Physics 2019-08-28 Tobias Dornheim

We present a unified theory of the variational Monte Carlo (VMC) and determinant quantum Monte Carlo (DQMC) methods using a novel density matrix formulation of VMC. We introduce an efficient algorithm for VMC to compute correlation…

Strongly Correlated Electrons · Physics 2018-10-02 Mohammad-Sadegh Vaezi , Abolhassan Vaezi