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We perform large-scale Quantum Monte Carlo (QMC) simulations for strongly interacting bosons in a 2D optical lattice trap, and confirm an excellent agreement with the benchmarking in-situ density measurements by the Chicago group [1]. We…

Quantum Gases · Physics 2011-03-16 Shiang Fang , Chia-Ming Chung , Ping Nang Ma , Pochung Chen , Daw-Wei Wang

Properties that are necessarily formulated within pure (symmetric) expectation values are difficult to calculate for projector quantum Monte Carlo approaches, but are critical in order to compute many of the important observable properties…

Computational Physics · Physics 2015-06-23 Catherine Overy , George H. Booth , N. S. Blunt , James Shepherd , Deidre Cleland , Ali Alavi

Being motivated by the surge of fermionic quantum Monte Carlo simulations at finite temperature, we present a detailed analysis of the permutation-cycle properties of path integral Monte Carlo (PIMC) simulations of degenerate electrons.…

Computational Physics · Physics 2019-07-24 Tobias Dornheim , Simon Groth , Alexei Filinov , Michael Bonitz

By means of detailed Monte Carlo (MC) simulations, we have presented dynamic phase transition (DPT) properties of ferromagnetic thin-films. Thermal variations of surface, bulk and total dynamical order parameters (DOP) for a film and total…

Statistical Mechanics · Physics 2016-01-06 Bahadır Ozan Aktaş , Erol Vatansever , Hamza Polat

In a typical finite temperature quantum Monte Carlo (QMC) simulation, estimators for simple static observables such as specific heat and magnetization are known. With a great deal of system-specific manual labor, one can sometimes also…

Statistical Mechanics · Physics 2026-01-30 Nic Ezzell , Itay Hen

By using stochastic ensembles of walkers in physical and in one-body Hilbert spaces the recently proposed time-dependent quantum Monte Carlo (TDQMC) method offers the unique capability to calculate one-body density matrices at fully…

Quantum Physics · Physics 2025-02-07 Ivan P. Christov

One bottleneck of quantum Monte Carlo (QMC) simulation of strongly correlated electron systems lies at the scaling relation of computational complexity with respect to the system sizes. For generic lattice models of interacting fermions,…

Strongly Correlated Electrons · Physics 2019-02-20 Zi Hong Liu , Xiao Yan Xu , Yang Qi , Kai Sun , Zi Yang Meng

The results of analytical approximations and extensive calculations based on a path integral Monte Carlo (PIMC) scheme are presented. A new (direct) PIMC method allows for a correct determination of thermodynamic properties such as energy…

Astrophysics · Physics 2007-05-23 V. Filinov , M. Bonitz , D. Kremp , W. -D. Kraeft , V. Fortov

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

In the last few years we have been developing a Monte Carlo simulation method to cope with systems of many electrons and ions in the Born-Oppenheimer (BO) approximation, the Coupled Electron-Ion Monte Carlo Method (CEIMC). Electronic…

Computational Physics · Physics 2007-05-23 Carlo Pierleoni , David M. Ceperley

Unbiased stochastic sampling of the one- and two-body reduced density matrices is achieved in full configuration interaction quantum Monte Carlo with the introduction of a second, "replica" ensemble of walkers, whose population evolves in…

Computational Physics · Physics 2015-09-02 Robert E. Thomas , Daniel Opalka , Catherine Overy , Peter J. Knowles , Ali Alavi , George H. Booth

We present a new approach to the study of equilibrium properties in many-body quantum physics. Our method takes inspiration from Density Matrix Quantum Monte Carlo and incorporates new crucial features. First of all, the dynamics is…

Quantum Physics · Physics 2022-01-06 Romain Chessex , Massimo Borrelli , Hans Christian Öttinger

We present a diagrammatic Monte Carlo method for quantum impurity problems with general interactions and general hybridization functions. Our method uses a recursive determinant scheme to sample diagrams for the scattering amplitude. Unlike…

Strongly Correlated Electrons · Physics 2020-08-13 Jia Li , Markus Wallerberger , Emanuel Gull

The following electromagnetism (EM) inverse problem is addressed. It consists in estimating local radioelectric properties of materials recovering an object from global EM scattering measurements, at various incidences and wave frequencies.…

Applications · Statistics 2015-06-12 François Giraud , Pierre Minvielle , Pierre Del Moral

We here apply the recently developed initiator density matrix quantum Monte Carlo (i-DMQMC) to a wide range of chemical environments using atoms and molecules in vacuum. i-DMQMC samples the exact density matrix of a Hamiltonian at finite…

Chemical Physics · Physics 2019-12-03 Hayley R. Petras , Sai Kumar Ramadugu , Fionn D. Malone , James J. Shepherd

We present a variational density matrix approach to the thermal properties of interacting fermions in the continuum. The variational density matrix is parametrized by a permutation equivariant many-body unitary transformation together with…

Strongly Correlated Electrons · Physics 2022-04-04 Hao Xie , Linfeng Zhang , Lei Wang

We present iterative Monte Carlo algorithm for which the temperature variable is attracted by a critical point. The algorithm combines techniques of single histogram reweighting and linear filtering. The 2d Ising model of ferromagnet is…

Statistical Mechanics · Physics 2015-06-24 M. Gmitra , D. Horvath

At low temperatures $T$ where $1/T=\beta\gg1$ the na\"ive implementation of determinant quantum Monte Carlo (DQMC) methods suffers from loss of precision and numerical instabilities when evaluating the fermion determinant. This instability…

Computational Physics · Physics 2026-04-02 Thomas Luu , Johann Ostmeyer , Petar Sinilkov , Finn L. Temmen

We propose an efficient method for Monte Carlo simulation of quantum lattice models. Unlike most other quantum Monte Carlo methods, a single run of the proposed method yields the free energy and the entropy with high precision for the whole…

Statistical Mechanics · Physics 2009-11-10 Chiaki Yamaguchi , Naoki Kawashima , Yutaka Okabe

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