English
Related papers

Related papers: Imaginary Time Correlations and the phaseless Auxi…

200 papers

Quantum simulators offer great potential for investigating dynamical properties of quantum field theories. However, preparing accurate non-trivial initial states for these simulations is challenging. Classical Euclidean-time Monte-Carlo…

Quantum Physics · Physics 2025-06-04 Navya Gupta , Christopher David White , Zohreh Davoudi

The interaction and exchange-correlation contributions to the ground-state energy of an arbitrary many-electron system can be obtained from a spherical average of the wavevector-dependent diagonal structure factor (SF). We model the…

Materials Science · Physics 2015-06-25 R. Gaudoin , J. M. Pitarke

When a system undergoes a quantum phase transition, the ground-state wave-function shows a change of nature, which can be monitored using the fidelity concept. We introduce two Quantum Monte Carlo schemes that allow the computation of…

Strongly Correlated Electrons · Physics 2009-10-21 David Schwandt , Fabien Alet , Sylvain Capponi

A new computational method for finite-temperature properties of strongly correlated electrons is proposed by extending the variational Monte Carlo method originally developed for the ground state. The method is based on the path integral in…

Strongly Correlated Electrons · Physics 2016-06-10 Kensaku Takai , Kota Ido , Takahiro Misawa , Youhei Yamaji , Masatoshi Imada

Within the imaginary-time theory for nonequilibrium in quantum dot systems the calculation of dynamical quantities like Green's functions is possible via a suitable quantum Monte-Carlo algorithm. The challenging task is to analytically…

Strongly Correlated Electrons · Physics 2013-07-04 Andreas Dirks , Jong E. Han , Mark Jarrell , Thomas Pruschke

We present an implementation of phaseless Auxiliary-Field Quantum Monte Carlo (ph-AFQMC) utilizing graphical processing units (GPUs). The AFQMC method is recast in terms of matrix operations which are spread across thousands of processing…

Computational Physics · Physics 2018-09-07 James Shee , Evan J. Arthur , Shiwei Zhang , David R. Reichman , Richard A. Friesner

We describe a new algorithm for the numerical simulation of quantum spin and boson systems. The method is based on the Trotter decomposition in imaginary time and a decoupling by auxiliary Ising spins. It can be applied, in principle, to…

Disordered Systems and Neural Networks · Physics 2009-10-31 M. Ulmke , R. T. Scalettar

In this paper, we solve quantum many-body problem by propagating ensembles of trajectories and guiding waves in physical space. We introduce the 'effective potential' correction within the recently proposed time-dependent quantum Monte…

Quantum Physics · Physics 2025-02-05 Ivan P. Christov

We present phaseless auxiliary-field (AF) quantum Monte Carlo (QMC) calculations of the ground states of some hydrogen-bonded systems. These systems were selected to test and benchmark different aspects of the new phaseless AF QMC method.…

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

The recently developed auxiliary field diffusion Monte Carlo method is applied to compute the equation of state and the compressibility of neutron matter. By combining diffusion Monte Carlo for the spatial degrees of freedom and auxiliary…

Nuclear Theory · Physics 2009-11-10 A. Sarsa , S. Fantoni , K. E. Schmidt , F. Pederiva

To make useful connections with experimental measurements, correlated electronic structure theories must accurately predict chemical properties in addition to energies. We present a finite-difference based algorithm to compute first-order…

Chemical Physics · Physics 2025-09-24 Leon Otis , Sri Gudivada , Marvin Friede , James Shee

Recently Han and Heary proposed an approach to steady-state quantum transport through mesoscopic structures, which maps the non-equilibrium problem onto a family of auxiliary quantum impurity systems subject to imaginary voltages. We employ…

Strongly Correlated Electrons · Physics 2012-05-07 Andreas Dirks , Philipp Werner , Mark Jarrell , Thomas Pruschke

The Auxiliary Field Diffusion Monte Carlo method has been applied to simulate droplets of 7 and 8 neutrons. Results for realistic nucleon-nucleon interactions, which include tensor, spin--orbit and three--body forces, plus a standard…

Nuclear Theory · Physics 2009-11-10 Francesco Pederiva , A. Sarsa , K. E. Schmidt , S. Fantoni

A quantum Monte Carlo method with non-local update scheme is presented. The method is based on a path-integral decomposition and a worm operator which is local in imaginary time. It generates states with a fixed number of particles and…

Statistical Mechanics · Physics 2009-11-11 Kris Van Houcke , Stefan Rombouts , Lode Pollet

We investigate the viability of the phaseless finite temperature auxiliary field quantum Monte Carlo (ph-FT-AFQMC) method for ab initio systems using the uniform electron gas as a model. Through comparisons with exact results and finite…

Chemical Physics · Physics 2021-02-15 Joonho Lee , Miguel A. Morales , Fionn D. Malone

A generalized version of the valence-bond Monte Carlo method is used to study ground state properties of the 1+1 dimensional quantum $Q$-state Potts models. For appropriate values of $Q$ these models can be used to describe interacting…

Disordered Systems and Neural Networks · Physics 2010-08-20 Huan Tran , N. E. Bonesteel

We report tests of the recently proposed multicanonical multigrid Monte Carlo method for the two-dimensional $\Phi^4$ field theory. Defining an effective autocorrelation time we obtain real time improvement factors of about one order of…

High Energy Physics - Lattice · Physics 2009-10-22 W. Janke , T. Sauer

We describe a Fourier Accelerated Hybrid Monte Carlo algorithm suitable for dynamical fermion simulations of non-gauge models. We test the algorithm in supersymmetric quantum mechanics viewed as a one-dimensional Euclidean lattice field…

High Energy Physics - Lattice · Physics 2011-07-28 S. Catterall , S. Karamov

Here the recently proposed time-dependent quantum Monte Carlo method is applied to three dimensional para- and ortho-helium atoms subjected to an external electromagnetic field with amplitude sufficient to cause significant ionization. By…

Atomic Physics · Physics 2025-02-05 Ivan P. Christov

Monte Carlo simulation techniques, like simulated annealing and parallel tempering, are often used to evaluate low-temperature properties and find ground states of disordered systems. Here we compare these methods using direct calculations…

Disordered Systems and Neural Networks · Physics 2007-05-23 J. J. Moreno , H. G. Katzgraber , Alexander K. Hartmann