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Related papers: Relieving the fermionic and the dynamical sign pro…

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We discuss the Fermion sign problem and, by examining a very general Hubbard-Stratonovich (HS) transformation, argue that the sign problem cannot be solved with such methods. We propose a different kind of transformation which, while not…

Condensed Matter · Physics 2011-08-11 Ghassan George Batrouni , Philippe de Forcrand

Quantum Monte Carlo (QMC) simulations constitute nowadays one of the most powerful methods to study strongly correlated quantum systems, provided that no "sign problem" arises. However, many systems of interest, including highly frustrated…

Strongly Correlated Electrons · Physics 2022-03-30 Andreas Honecker , Lukas Weber , Philippe Corboz , Frédéric Mila , Stefan Wessel

A method is presented to tackle the sign problem in the simulations of systems having indefinite or complex-valued measures. In general, this new approach is shown to yield statistical errors smaller than the crude Monte Carlo using…

High Energy Physics - Lattice · Physics 2008-11-26 T D Kieu , C J Griffin

The quantum Monte-Carlo method is applied to two-dimensional electron systems under strong magnetic fields. The negative-sign problem involved by this method can be avoided for certain filling factors by modifying interaction parameters…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Sei Suzuki , Tatsuya Nakajima

Treating the fermionic ground state problem as a constrained stochastic optimization problem, a formalism for fermionic quantum Monte Carlo is developed that makes no reference to a trial wavefunction. Exchange symmetry is enforced by…

Strongly Correlated Electrons · Physics 2020-10-14 Michael Hutcheon

We formulate a path-integral Monte Carlo algorithm for simulating lattice systems consisting of fictitious particles governed by a generalized exchange statistics. This method, initially proposed for continuum systems, introduces a…

Strongly Correlated Electrons · Physics 2025-08-19 Zhijie Fan , Tianning Xiao , Youjin Deng

Numerical simulations of numerous quantum systems suffer from the notorious sign problem. Meron-cluster algorithms lead to an efficient solution of sign problems for both fermionic and bosonic models. Here we apply the meron concept to…

Statistical Mechanics · Physics 2007-05-23 S. Chandrasekharan , B. Scarlet , U. -J. Wiese

We demonstrate, by considering the triangular lattice spin-1/2 Heisenberg model, that Monte Carlo sampling of skeleton Feynman diagrams within the fermionization framework offers a universal first-principles tool for strongly correlated…

Strongly Correlated Electrons · Physics 2013-04-09 S. A. Kulagin , N. Prokof'ev , O. A. Starykh , B. Svistunov , C. N. Varney

We show how the sign problem occurring in dynamical simulations of random matrices at nonzero chemical potential can be avoided by judiciously combining matrices into subsets. For each subset the sum of fermionic determinants is real and…

High Energy Physics - Lattice · Physics 2011-11-22 Jacques Bloch

We consider the problem of estimating the probability of a large loss from a financial portfolio, where the future loss is expressed as a conditional expectation. Since the conditional expectation is intractable in most cases, one may…

Numerical Analysis · Mathematics 2020-11-25 Zhenghang Xu , Zhijian He , Xiaoqun Wang

Cluster algorithms have been recently used to eliminate sign problems that plague Monte-Carlo methods in a variety of systems. In particular such algorithms can also be used to solve sign problems associated with the permutation of fermion…

High Energy Physics - Lattice · Physics 2015-06-25 Shailesh Chandrasekharan

We present a simulation algorithm for dynamical fermions that combines the multiboson technique with the Hybrid Monte Carlo algorithm. We find that the algorithm gives a substantial gain over the standard methods in practical simulations.…

High Energy Physics - Lattice · Physics 2009-10-30 Roberto Frezzotti , Karl Jansen

Ab-initio Monte Carlo simulations of strongly-interacting fermionic systems are plagued by the fermion sign problem, making the non-perturbative study of many interesting regimes of dense quantum matter, or of theories of odd numbers of…

High Energy Physics - Lattice · Physics 2024-03-05 Debasish Banerjee , Emilie Huffman

We propose a multilevel Monte Carlo method for a particle-based asymptotic-preserving scheme for kinetic equations. Kinetic equations model transport and collision of particles in a position-velocity phase-space. With a diffusive scaling,…

Numerical Analysis · Mathematics 2020-05-21 Emil Løvbak , Giovanni Samaey , Stefan Vandewalle

The calculation of the ground state and thermodynamics of mass-imbalanced Fermi systems is a challenging many-body problem. Even in one spatial dimension, analytic solutions are limited to special configurations and numerical progress with…

Quantum Gases · Physics 2018-07-20 Lukas Rammelmüller , William J. Porter , Joaquín E. Drut , Jens Braun

Due to the intrinsic complexity of the quantum many-body problem, quantum Monte Carlo algorithms and their corresponding Monte Carlo configurations can be defined in various ways. Configurations corresponding to few Feynman diagrams often…

Strongly Correlated Electrons · Physics 2019-04-30 Alexander Kowalski , Andreas Hausoel , Markus Wallerberger , Patrik Gunacker , Giorgio Sangiovanni

The sign problem is a notorious problem, which occurs in Monte Carlo simulations of a system with a partition function whose integrand is not positive. One way to simulate such a system is to use the factorization method where one enforces…

High Energy Physics - Lattice · Physics 2012-11-08 Konstantinos N. Anagnostopoulos , Takehiro Azuma , Jun Nishimura

We develop a strong-coupling perturbation scheme for a generic Hubbard model around a half-filled particle-hole-symmetric reference system, which is free from the fermionic sign problem. The approach is based on the lattice determinantal…

Strongly Correlated Electrons · Physics 2026-05-15 Sergei Iskakov , Mikhail I. Katsnelson , Alexander I. Lichtenstein

The bilayer Hubbard model describes the antiferromagnet to spin singlet transition and, potentially, aspects of the physics of unconventional superconductors. Despite these important applications, significant aspects of its `phase diagram'…

Strongly Correlated Electrons · Physics 2022-09-19 Yingping Mou , Rubem Mondaini , Richard T. Scalettar

We present a simple, robust and highly efficient method for optimizing all parameters of many-body wave functions in quantum Monte Carlo calculations, applicable to continuum systems and lattice models. Based on a strong zero-variance…

Other Condensed Matter · Physics 2009-11-11 C. J. Umrigar , Julien Toulouse , Claudia Filippi , S. Sorella , R. G. Hennig
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