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Related papers: Mitigating the Hubbard Sign Problem with Complex-V…

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We apply constant imaginary offsets to the path integral for a reduction of the sign problem in the Hubbard model. These simple transformations enhance the quality of results from HMC calculations without compromising the speed of the…

Strongly Correlated Electrons · Physics 2024-07-11 Christoph Gäntgen , Evan Berkowitz , Thomas Luu , Johann Ostmeyer , Marcel Rodekamp

Towards a solution to the sign problem in the simulations of systems having indefinite or complex-valued measures, we propose a new approach which yields statistical errors smaller than the crude Monte Carlo using absolute values of the…

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

Monte Carlo simulations are a powerful tool for elucidating the properties of complex systems across many disciplines. Not requiring any a priori knowledge, they are particularly well suited for exploring new phenomena. However, when…

Strongly Correlated Electrons · Physics 2016-03-02 Mauro Iazzi , Alexey A. Soluyanov , Matthias Troyer

It is shown that a class of separately frustration-free (SFF) Hamiltonians can be Monte Carlo simulated efficiently on a classical computing machine, because such an SFF Hamiltonian corresponds to a Gibbs wavefunction whose nodal structure…

General Physics · Physics 2021-12-30 David H. Wei

We review recent attempts at dealing with the sign problem in Monte Carlo calculations by deforming the region of integration in the path integral from real to complex fields. We discuss the theoretical foundations, the algorithmic issues…

High Energy Physics - Lattice · Physics 2018-04-18 Paulo F. Bedaque

Sign problem in quantum Monte Carlo (QMC) simulation appears to be an extremely hard yet interesting problem. In this article, we present a pedagogical overview on the origin of the sign problem in various quantum Monte Carlo simulation…

Strongly Correlated Electrons · Physics 2023-10-27 Gaopei Pan , Zi Yang Meng

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

Quantum Monte Carlo (QMC) methods offer exact solutions for quantum many-body systems but face severe limitations in fermionic systems like atomic nuclei due to the sign problem. While sign-problem-free QMC algorithms exist and provide…

Nuclear Theory · Physics 2026-01-06 Zhong-Wang Niu , Bing-Nan Lu

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

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

As an intrinsically unbiased method, the quantum Monte Carlo (QMC) method is of unique importance in simulating interacting quantum systems. Although the QMC method often suffers from the notorious sign problem, the sign problem of quantum…

Strongly Correlated Electrons · Physics 2023-08-03 Zhou-Quan Wan , Shi-Xin Zhang , Hong Yao

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

For some models of interacting fermions the known solution to the notorious sign-problem in Monte Carlo (MC) simulations is to work with macroscopic fermionic determinants; the price, however, is a macroscopic scaling of the numerical…

Strongly Correlated Electrons · Physics 2009-11-10 Evgueni Bourovski , Nikolay Prokof'ev , Boris Svistunov

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

Monte Carlo simulations are useful tools for modeling quantum systems, but in some cases they suffer from a sign problem, leading to an exponential slow down in their convergence to a value. While solving the sign problem is generically…

Quantum Physics · Physics 2022-12-21 T. C. Mooney , Jacob Bringewatt , Neill C. Warrington , Lucas T. Brady

We describe a procedure for alleviating the fermion sign problem in which phase fluctuations are explicitly subtracted from the Boltzmann factor. Several ans\"atze for fluctuations are designed and compared. In the absence of a sufficiently…

High Energy Physics - Lattice · Physics 2023-07-11 Scott Lawrence , Yukari Yamauchi

A method is proposed to handle the sign problem in the simulation of systems having indefinite or complex-valued measures. In general, this new approach, which is based on renormalisation blocking, is shown to yield statistical errors…

High Energy Physics - Lattice · Physics 2009-10-28 J. F. Markham , T. D. Kieu

The notorious sign problem severely limits the applicability of quantum Monte Carlo (QMC) simulations, as statistical errors grow exponentially with system size and inverse temperature. A recent proposal of a quantum-computing stochastic…

Quantum Physics · Physics 2026-03-11 Kwai-Kong Ng , Min-Fong Yang

We propose a mechanism for solving the `negative sign problem'---the inability to assign non-negative weights to quantum Monte Carlo configurations---for a toy model consisting of a frustrated triplet of spin-$1/2$ particles interacting…

Statistical Mechanics · Physics 2019-04-03 Itay Hen

We present a strategy to alleviate the sign problem in continuous-time quantum Monte Carlo (CTQMC) simulations of the dynamical-mean-field-theory (DMFT) equations for the spin-orbit-coupled multiorbital Hubbard model. We first identify the…

Strongly Correlated Electrons · Physics 2020-01-22 Aaram J. Kim , Philipp Werner , Roser Valentí