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Related papers: Imaginary Time Correlations and the phaseless Auxi…

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We present an elementary and self-contained account of the analogies existing between classical diffusion and the imaginary-time evolution of quantum systems. These analogies are used to develop a new quantum simulation method which allows…

Condensed Matter · Physics 2007-05-23 S. Baroni , S. Moroni

The auxiliary-field quantum Monte Carlo (AFMC) method is a powerful and widely used technique for ground-state and finite-temperature simulations of quantum many-body systems. We introduce several algorithmic improvements for…

Computational Physics · Physics 2021-03-18 C. N. Gilbreth , S. Jensen , Y. Alhassid

We explore correlated electron states in harmonically confined few-electron quantum dots in an external magnetic field by the path-integral Monte Carlo method for a wide range of the field and the Coulomb interaction strength. Using the…

Strongly Correlated Electrons · Physics 2020-01-07 Csaba Tőke , Tamás Haidekker Galambos

Many experimentally-accessible, finite-sized interacting quantum systems are most appropriately described by the canonical ensemble of statistical mechanics. Conventional numerical simulation methods either approximate them as being coupled…

Strongly Correlated Electrons · Physics 2023-05-23 Tong Shen , Hatem Barghathi , Jiangyong Yu , Adrian Del Maestro , Brenda Rubenstein

Nuclear structure quantum Monte Carlo methods such as Green's function or auxiliary field diffusion Monte Carlo have used phenomenological local real-space potentials containing as few derivatives as possible, such as the Argonne-Urbana…

Nuclear Theory · Physics 2012-07-27 J. E. Lynn , K. E. Schmidt

We propose a quantum Monte Carlo approach to solve the ground state many-body Schrodinger equation for the electronic ground state. The method combines optimization from variational Monte Carlo and propagation from auxiliary field quantum…

Computational Physics · Physics 2023-04-21 Yixiao Chen , Linfeng Zhang , Weinan E , Roberto Car

We present near-term quantum algorithms for auxiliary-field quantum Monte Carlo (AFQMC), viewed as imaginary-time projection for ground-state calculation as an ensemble of one-body propagators driven by stochastic fields $\Omega$. Starting…

Quantum Physics · Physics 2026-03-31 Xiantao Li

We generalize the recently developed diagrammatic Monte Carlo techniques for quantum impurity models from an imaginary time to a Keldysh formalism suitable for real-time and nonequilibrium calculations. Both weak-coupling and…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Philipp Werner , Takashi Oka , Andrew J. Millis

Quantum simulators hold great promise for studying real-time (Minkowski) dynamics of quantum field theories. Nonetheless, preparing non-trivial initial states remains a major obstacle. Euclidean-time Monte-Carlo methods yield ground-state…

High Energy Physics - Lattice · Physics 2025-10-30 Navya Gupta , Christopher David White , Zohreh Davoudi

Auxiliary Field Quantum Monte Carlo (AFQMC) has emerged as a powerful framework for treating strongly correlated electronic systems, offering a favorable balance between computational cost and accuracy. In this paper, we present a novel…

Chemical Physics · Physics 2026-04-03 Maxine Luo , Victor Chen , Yu Wang , Christian B. Mendl

We present the ground state extension of the efficient quantum Monte Carlo algorithm for lattice fermions of arXiv:1411.0683. Based on continuous-time expansion of imaginary-time projection operator, the algorithm is free of systematic…

Strongly Correlated Electrons · Physics 2015-07-02 Lei Wang , Mauro Iazzi , Philippe Corboz , Matthias Troyer

We present a generalization of the phaseless auxiliary-field quantum Monte Carlo (AFQMC) method to cavity quantum-electrodynamical (QED) matter systems. The method can be formulated in both the Coulomb and the dipole gauge. We verify its…

Chemical Physics · Physics 2025-03-04 Lukas Weber , Leonardo dos Anjos Cunha , Miguel A. Morales , Angel Rubio , Shiwei Zhang

We formulate a quantum Monte Carlo (QMC) method for calculating the ground state of many-boson systems. The method is based on a field-theoretical approach, and is closely related to existing fermion auxiliary-field QMC methods which are…

Computational Physics · Physics 2009-11-10 Wirawan Purwanto , Shiwei Zhang

Quantum Monte Carlo methods are used to calculate various ground state properties of charged bosons in two dimensions, throughout the whole density range where the fluid phase is stable. Wigner crystallization is predicted at $r_s\simeq…

Condensed Matter · Physics 2018-05-01 S. De Palo , S. Conti , S. Moroni

We have used the variational and diffusion quantum Monte Carlo methods to calculate the energy, pair correlation function, static structure factor, and momentum density of the ground state of the two-dimensional homogeneous electron gas. We…

Mesoscale and Nanoscale Physics · Physics 2010-03-02 N. D. Drummond , R. J. Needs

We extend the recently introduced phaseless auxiliary-field quantum Monte Carlo (QMC) approach to any single-particle basis, and apply it to molecular systems with Gaussian basis sets. QMC methods in general scale favorably with system…

Computational Physics · Physics 2007-05-23 W. A. Al-Saidi , Shiwei Zhang , Henry Krakauer

We present a quantum Monte Carlo method which allows calculations on many-fermion systems at finite temperatures without any sign decay. This enables simulations of the grand-canonical ensemble at large system sizes and low temperatures.…

Condensed Matter · Physics 2009-10-31 Shiwei Zhang

We address the computation of ground-state properties of chemical systems and realistic materials within the auxiliary-field quantum Monte Carlo method. The phase constraint to control the fermion phase problem requires the random walks in…

Strongly Correlated Electrons · Physics 2017-11-28 Mario Motta , Shiwei Zhang

A diffusion Monte Carlo algorithm is introduced that can determine the correct nodal structure of the wave function of a few-fermion system and its ground-state energy without an uncontrolled bias. This is achieved by confining signed…

Computational Physics · Physics 2020-02-05 Alexander A. Kunitsa , So Hirata

New model-independent compact representations of imaginary-time data are presented in terms of the intermediate representation (IR) of analytical continuation. This is motivated by a recent numerical finding by the authors [J. Otsuki et…

Strongly Correlated Electrons · Physics 2017-07-26 Hiroshi Shinaoka , Junya Otsuki , Masayuki Ohzeki , Kazuyoshi Yoshimi