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Related papers: Sign Problems in Quantum Field Theory: Classical a…

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We discuss the sign problem arising in Monte Carlo simulations of frustrated quantum spin systems. We show that for a class of ``semi-frustrated'' systems (Heisenberg models with ferromagnetic couplings $J_z(r) < 0$ along the $z$-axis and…

Strongly Correlated Electrons · Physics 2009-10-31 Patrik Henelius , Anders W. Sandvik

We introduce a Quantum Monte Carlo (QMC) method which efficiently simulates in a sign-problem-free way a broad class of frustrated $S=1/2$ models with competing antiferromagnetic interactions. Our scheme uses the basis of total spin…

Strongly Correlated Electrons · Physics 2016-11-09 Fabien Alet , Kedar Damle , Sumiran Pujari

The infamous sign problem leads to an exponential complexity in Monte Carlo simulations of generic many-body quantum systems. Nevertheless, many phases of matter are known to admit a sign-problem-free representative, allowing efficient…

Strongly Correlated Electrons · Physics 2020-10-14 Omri Golan , Adam Smith , Zohar Ringel

We present results of the numerical simulation of the two-dimensional Thirring model at finite density and temperature. The severe sign problem is dealt with by deforming the domain of integration into complex field space. This is the first…

High Energy Physics - Lattice · Physics 2017-01-11 Andrei Alexandru , Gokce Basar , Paulo F. Bedaque , Gregory W. Ridgway , Neill C. Warrington

The "sign problem" (SP) is the fundamental limitation to simulations of strongly correlated materials in condensed matter physics, solving quantum chromodynamics at finite baryon density, and computational studies of nuclear matter. As a…

Strongly Correlated Electrons · Physics 2022-03-09 Rubem Mondaini , Sabyasachi Tarat , Richard T. Scalettar

Quantum Monte Carlo (QMC) methods are one of the most important tools for studying interacting quantum many-body systems. The vast majority of QMC calculations in interacting fermion systems require a constraint to control the sign problem.…

Strongly Correlated Electrons · Physics 2016-12-08 Mingpu Qin , Hao Shi , Shiwei Zhang

We point out that Monte Carlo simulations of theories with severe sign problems can be profitably performed over manifolds in complex space different from the one with fixed imaginary part of the action. We describe a family of such…

High Energy Physics - Lattice · Physics 2016-03-22 Andrei Alexandru , Gokce Basar , Paulo F. Bedaque , Gregory W. Ridgway , Neill C. Warrington

Building on recent solutions of the fermion sign problem for specific models we present two continuous-time quantum Monte Carlo methods for efficient simulation of mass-imbalanced Hubbard models on bipartite lattices at half-filling. For…

Strongly Correlated Electrons · Physics 2015-12-18 Ye-Hua Liu , Lei Wang

Quantum simulations are a powerful tool for exploring strongly correlated many-body phenomena. Yet, their reach is limited by the fermion sign problem, which causes configuration weights to become negative, compromising statistical…

Strongly Correlated Electrons · Physics 2025-12-04 Ryan Larson , Rubem Mondaini , Richard T. Scalettar

Mean-field molecular dynamics based on path integrals is used to approximate canonical quantum observables for particle systems consisting of nuclei and electrons. A computational bottleneck is the sampling from the Gibbs density of the…

Numerical Analysis · Mathematics 2023-11-30 Xin Huang , Petr Plechac , Mattias Sandberg , Anders Szepessy

The sign problem is a major obstacle in quantum Monte Carlo simulations for many-body fermion systems. We examine this problem with a new perspective based on the Majorana reflection positivity and Majorana Kramers positivity. Two…

Strongly Correlated Electrons · Physics 2018-01-19 Z. C. Wei , Congjun Wu , Yi Li , Shiwei Zhang , T. Xiang

Accurate thermodynamic simulations of correlated fermions using path integral Monte Carlo (PIMC) methods are of paramount importance for many applications such as the description of ultracold atoms, electrons in quantum dots, and warm-dense…

Computational Physics · Physics 2021-02-03 Tobias Dornheim , Michele Invernizzi , Jan Vorberger , Barak Hirshberg

Quantum computing promises the possibility of studying the real-time dynamics of nonperturbative quantum field theories while avoiding the sign problem that obstructs conventional lattice approaches. Current and near-future quantum devices…

High Energy Physics - Lattice · Physics 2021-12-15 Christopher Culver , David Schaich

Quantum Monte Carlo (QMC) is a family of powerful tools for addressing quantum many-body problems. However, its applications are often plagued by the fermionic sign problem. A promising strategy is to simulate an interaction without sign…

Nuclear Theory · Physics 2025-05-01 Jun Liu , Teng Wang , Bing-Nan Lu

Quantum computers have the potential to expand the utility of lattice gauge theory to investigate non-perturbative particle physics phenomena that cannot be accessed using a standard Monte Carlo method due to the sign problem. Thanks to the…

High Energy Physics - Lattice · Physics 2023-08-30 Emanuele Mendicelli

When one tries to simulate quantum spin systems by the Monte Carlo method, often the 'minus-sign problem' is encountered. In such a case, an application of probabilistic methods is not possible. In this paper the method has been proposed…

Statistical Mechanics · Physics 2009-11-11 Jacek Wojtkiewicz

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 present a guiding principle for designing fermionic Hamiltonians and quantum Monte Carlo (QMC) methods that are free from the infamous sign problem by exploiting the Lie groups and Lie algebras that appear naturally in the Monte Carlo…

Strongly Correlated Electrons · Physics 2015-12-23 Lei Wang , Ye-Hua Liu , Mauro Iazzi , Matthias Troyer , Gergely Harcos

A general algorithm toward the solution of the fermion sign problem in finite-temperature quantum Monte Carlo simulations has been formulated for discretized fermion path integrals with nearest-neighbor interactions in the Trotter…

Statistical Mechanics · Physics 2009-10-31 C. H. Mak , R. Egger , H. Weber-Gottschick

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