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Related papers: Imaginary Time Correlations and the phaseless Auxi…

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We evaluate imaginary time density-density correlation functions for a two-dimensional homogeneous electron gas using the phaseless auxiliary field quantum Monte Carlo method. We show that such methodology, once equipped with suitable…

Strongly Correlated Electrons · Physics 2015-09-04 M. Motta , D. E. Galli , S. Moroni , E. Vitali

The calculation of imaginary time displaced correlation functions with the auxiliary field projector quantum Monte-Carlo algorithm provides valuable insight (such as spin and charge gaps) in the model under consideration. One of the authors…

Strongly Correlated Electrons · Physics 2009-10-31 M. Feldbacher , F. F. Assaad

We present a method based on the Path Integral Monte Carlo formalism for the calculation of ground-state time correlation functions in quantum systems. The key point of the method is the consideration of time as a complex variable whose…

Statistical Mechanics · Physics 2015-06-24 Riccardo Rota , Joaquim Casulleras , Ferran Mazzanti , Jordi Boronat

Auxiliary-field quantum Monte Carlo methods enable the calculation of thermal and ground state properties of correlated quantum many-body systems in model spaces that are many orders of magnitude larger than those that can be treated by…

Nuclear Theory · Physics 2019-07-29 Y. Alhassid

We implement the phaseless auxiliary field quantum Monte Carlo method using the plane-wave based projector augmented wave method and explore the accuracy and the feasibility of applying our implementation to solids. We use a singular value…

We present a continuous-time Monte Carlo method for quantum impurity models, which combines a weak-coupling expansion with an auxiliary-field decomposition. The method is considerably more efficient than Hirsch-Fye and free of time…

Strongly Correlated Electrons · Physics 2008-06-02 Emanuel Gull , Philipp Werner , Olivier Parcollet , Matthias Troyer

Calculations of the binding energy of the transition metal oxide molecules TiO and MnO are presented, using a recently developed phaseless auxiliary field quantum Monte Carlo approach. This method maps the interacting many-body problem onto…

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

The auxiliary-field quantum Monte Carlo (AFQMC) method is a general numerical method for correlated many-electron systems, which is being increasingly applied in lattice models, atoms, molecules, and solids. Here we introduce the theory and…

Computational Physics · Physics 2021-02-24 Hao Shi , Shiwei Zhang

The auxiliary-field quantum Monte Carlo (AFQMC) method provides a computational framework for solving the time-independent Schroedinger equation in atoms, molecules, solids, and a variety of model systems by stochastic sampling. We…

Strongly Correlated Electrons · Physics 2018-07-19 Shiwei Zhang

We address the calculation of dynamical correlation functions for many fermion systems at zero temperature, using the auxiliary-field quantum Monte Carlo method. The two-dimensional Hubbard hamiltonian is used as a model system. Although…

Strongly Correlated Electrons · Physics 2016-08-24 Ettore Vitali , Hao Shi , Mingpu Qin , Shiwei Zhang

The accurate theoretical description of the dynamic properties of correlated quantum many-body systems such as the dynamic structure factor $S(\mathbf{q},\omega)$ constitutes an important task in many fields. Unfortunately, highly accurate…

Statistical Mechanics · Physics 2023-03-08 Tobias Dornheim , Zhandos Moldabekov , Panagiotis Tolias , Maximilian Böhme , Jan Vorberger

Monte Carlo simulations are performed in classical phase space for a one-dimensional quantum harmonic crystal. Symmetrization effects for spinless bosons and fermions are quantified. The algorithm is tested for a range of parameters against…

Quantum Physics · Physics 2019-04-25 Phil Attard

We show that the recently developed phaseless auxiliary-field quantum Monte Carlo (AFQMC) method can be used to study excited states, providing an alternative to standard quantum chemistry methods. The phaseless AFQMC approach, whose…

Computational Physics · Physics 2013-07-09 Wirawan Purwanto , Shiwei Zhang , Henry Krakauer

We discuss an alternative accurate Monte Carlo method to calculate the ground-state energy and related quantities for Laughlin states of the fractional quantum Hall effect in a disk geometry. This alternative approach allows us to obtain…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Orion Ciftja , Carlos Wexler

Numerically exact continuous-time Quantum Monte Carlo algorithm for finite fermionic systems with non-local interactions is proposed. The scheme is particularly applicable for general multi-band time-dependent correlations since it does not…

Strongly Correlated Electrons · Physics 2009-11-10 A. N. Rubtsov , A. I. Lichtenstein

Quantum Monte Carlo and semiclassical methods are used to solve two and four site cluster dynamical mean field approximations to the square lattice Hubbard model at half filling and strong coupling. The energy, spin correlation function,…

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

The auxiliary field diffusion Monte Carlo method uses imaginary-time projection techniques to accurately solve the ground-state wave function of atomic nuclei and infinite nuclear matter. In this work, we present a novel representation of…

Nuclear Theory · Physics 2024-07-23 Jordan M. R. Fox , Alessandro Lovato , Alessandro Roggero , Ermal Rrapaj

An efficient Path Integral Monte Carlo procedure is proposed to simulate the behavior of quantum many-body dissipative systems described within the framework of the influence functional. Thermodynamic observables are obtained by Monte Carlo…

Statistical Mechanics · Physics 2009-11-07 Luca Capriotti , Alessandro Cuccoli , Andrea Fubini , Valerio Tognetti , Ruggero Vaia

The problem of calculating real-time correlation functions is formulated in terms of an imaginary-time partial differential equation. The latter is solved analytically for the perturbed harmonic oscillator and compared with the known exact…

Statistical Mechanics · Physics 2007-05-23 P. E. Kornilovitch

We present an \textit{ab initio} auxiliary field quantum Monte Carlo method for studying the electronic structure of molecules, solids, and model Hamiltonians at finite temperature. The algorithm marries the \textit{ab initio} phaseless…

Strongly Correlated Electrons · Physics 2018-11-13 Yuan Liu , Minsik Cho , Brenda Rubenstein
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