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Related papers: Symmetry in Auxiliary-Field Quantum Monte Carlo Ca…

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We develop a local correlation variant of auxiliary field quantum Monte Carlo (AFQMC) that is based on local natural orbitals (LNO-AFQMC). In LNO-AFQMC, independent AFQMC calculations are performed for each localized occupied orbital using…

Chemical Physics · Physics 2023-08-25 Jo S. Kurian , Hong-Zhou Ye , Ankit Mahajan , Timothy C. Berkelbach , Sandeep Sharma

We develop a new $\it {symmetrized}$ version of the Projector Quantum Monte Carlo (SPQMC) method which preserves the symmetries of the system by simultaneously sampling all symmetry related Ising configurations at each MC step and use it to…

Condensed Matter · Physics 2007-05-23 Bhargavi Srinivasan , S. Ramasesha , H. R. Krishnamurthy

We have studied electron correlations in the doped two-dimensional (2D) Hubbard model by using the coupled-cluster method (CCM) to investigate whether or not the method can be applied to correct the independent particle approximations…

Strongly Correlated Electrons · Physics 2009-10-31 Yoshihiro Asai , Hideki Katagiri

Within Full Configuration Interaction Quantum Monte Carlo, we investigate how the statistical error behaves as a function of the parameters which control the stochastic sampling. We define the inefficiency as a measure of the statistical…

Chemical Physics · Physics 2016-03-15 W. A. Vigor , J. S. Spencer , M. J. Bearpark , A. J. W. Thom

The most advanced techniques using fault-tolerant quantum computers to estimate the ground-state energy of a chemical Hamiltonian involve compression of the Coulomb operator through tensor factorizations, enabling efficient block-encodings…

Bond stretching mimics different levels of electron correlation and provides a challenging testbed for approximate many-body computational methods. Using the recently developed phaseless auxiliary-field quantum Monte Carlo (AF QMC) method,…

Computational Physics · Physics 2007-10-10 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

Quantum Monte Carlo (QMC) methods are powerful approaches for solving electronic structure problems. Although they often provide high-accuracy solutions, the precision of most QMC methods is ultimately limited by a trial wave function that…

Quantum Physics · Physics 2025-03-13 Nick S. Blunt , Laura Caune , Javiera Quiroz-Fernandez

The development of numerical methods capable of simulating realistic materials with strongly correlated electrons, with controllable errors, is a central challenge in quantum many-body physics. Here we describe how a hybrid between…

Strongly Correlated Electrons · Physics 2015-04-23 Alexei A. Kananenka , Emanuel Gull , Dominika Zgid

Quantum Monte Carlo methods provide in principle an accurate treatment of the many-body problem of the ground and excited states of condensed systems. In practice, however, uncontrolled errors such as those arising from the fixed-node and…

Materials Science · Physics 2012-03-27 William W. Tipton , Neil D. Drummond , Richard G. Hennig

We revisit the accuracy of the variational Monte Carlo (VMC) method by taking an example of ground state properties for the one-dimensional Hubbard model. We start from the variational wave functions with the Gutzwiller and long-range…

Strongly Correlated Electrons · Physics 2013-08-13 Ryui Kaneko , Satoshi Morita , Masatoshi Imada

Self-learning Monte Carlo method (SLMC), using a trained effective model to guide Monte Carlo sampling processes, is a powerful general-purpose numerical method recently introduced to speed up simulations in (quantum) many-body systems. In…

Strongly Correlated Electrons · Physics 2018-07-18 Chuang Chen , Xiao Yan Xu , Junwei Liu , George Batrouni , Richard Scalettar , Zi Yang Meng

A simple, general and practically exact method is developed to calculate the ground states of 1D macroscopic quantum systems with translational symmetry. Applied to the Hubbard model, a modest calculation reproduces the Bethe Ansatz…

Strongly Correlated Electrons · Physics 2015-05-19 S. G. Chung

We develop and test Quantum Monte Carlo algorithms which use a``twist'' or a phase in the wave function for fermions in periodic boundary conditions. For metallic systems, averaging over the twist results in faster convergence to the…

Statistical Mechanics · Physics 2009-02-06 C. Lin , F. -H. Zong , D. M. Ceperley

We tutorially review the determinantal Quantum Monte Carlo method for fermionic systems, using the Hubbard model as a case study. Starting with the basic ingredients of Monte Carlo simulations for classical systems, we introduce aspects…

Strongly Correlated Electrons · Physics 2007-05-23 Raimundo R. dos Santos

We discuss here some aspects related to the symmetries of a quantum many-body problem when trying to treat it on a quantum computer. Several features related to symmetry conservation, symmetry breaking, and possible symmetry restoration are…

Quantum Physics · Physics 2023-01-25 Denis Lacroix , Edgar Andres Ruiz Guzman , Pooja Siwach

The matrix element technique provides a superior statistical sensitivity for precision measurements of important parameters at hadron colliders, such as the mass of the top quark or the cross section for the production of Higgs bosons. The…

High Energy Physics - Experiment · Physics 2014-11-20 Oleg Brandt , Gaston Gutierrez , Michael H. L. S. Wang , Zhenyu Ye

Even with the recent rapid developments in quantum hardware, noise remains the biggest challenge for the practical applications of any near-term quantum devices. Full quantum error correction cannot be implemented in these devices due to…

Quantum Physics · Physics 2021-09-22 Zhenyu Cai

We present an accurate numerical study of the equation of state of nuclear matter based on realistic nucleon--nucleon interactions by means of Auxiliary Field Diffusion Monte Carlo (AFDMC) calculations. The AFDMC method samples the spin and…

Nuclear Theory · Physics 2007-05-23 S. Gandolfi , F. Pederiva , S. Fantoni , K. E. Schmidt

Phaseless Auxiliary-Field Quantum Monte Carlo (ph-AFQMC) has recently emerged as a promising method for the production of benchmark-level simulations of medium to large-sized molecules, due to its accuracy and favorable polynomial scaling…