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Related papers: Fermion Bag Approach to Fermion Sign Problems

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We propose a new approach to the fermion sign problem in systems where there is a coupling $U$ such that when it is infinite the fermions are paired into bosons and there is no fermion permutation sign to worry about. We argue that as $U$…

High Energy Physics - Lattice · Physics 2014-11-20 Shailesh Chandrasekharan

We present a new approach to some four-fermion lattice field theories which we call the generalized fermion bag approach. The basic idea is to identify unpaired fermionic degrees of freedom that cause sign problems and collect them in a…

High Energy Physics - Lattice · Physics 2011-12-01 Shailesh Chandrasekharan , Anyi Li

The fermion bag is a powerful idea that helps to solve fermion lattice field theories using Monte Carlo methods. Some sign problems that had remained unsolved earlier can be solved within this framework. In this work we argue that the…

High Energy Physics - Lattice · Physics 2014-12-12 Shailesh Chandrasekharan

Lattice four-fermion models containing $N$ flavors of staggered fermions, that are invariant under $Z_2$ and U(1) chiral symmetries, are known to suffer from sign problems when formulated using the auxiliary field approach. Although these…

High Energy Physics - Lattice · Physics 2015-06-12 Anyi Li

Lattice four-fermion models containing $N$ flavors of staggered fermions, that are invariant under $Z_2$ and U(1) chiral symmetries, are known to suffer from sign problems when formulated using the auxiliary field approach. Although these…

High Energy Physics - Lattice · Physics 2013-05-30 Shailesh Chandrasekharan , Anyi Li

We present a solution to the sign problem in a class of particle-hole symmetric Hamiltonian lattice fermion models on bipartite lattices using the idea of fermion bags. The solution remains valid when the particle-hole symmetry is broken…

High Energy Physics - Lattice · Physics 2015-12-03 Emilie Huffman , Shailesh Chandrasekharan

The recently proposed fermion bag approach is a powerful technique to solve some four-fermion lattice field theories. Due to the existence of a duality between strong and weak couplings, the approach leads to efficient Monte Carlo…

High Energy Physics - Lattice · Physics 2012-04-10 Shailesh Chandrasekharan , Anyi Li

We prove that sign problems in the traditional approach to some lattice Yukawa models can be completely solved when the fermions are formulated using fermion bags and the bosons are formulated in the worldline representation. We prove this…

High Energy Physics - Lattice · Physics 2013-05-30 Shailesh Chandrasekharan

We propose a framework based on the concept of the semigroup to understand the fermion sign problem. By using properties of contraction semigroups, we obtain sufficient conditions for quantum lattice fermion models to be sign-problem-free.…

Strongly Correlated Electrons · Physics 2024-08-28 Zhong-Chao Wei

We solve the sign problem in a particle-hole symmetric spin-polarized fermion model on bipartite lattices using the idea of fermion bags. The solution can be extended to a class of models at half filling but without particle-hole symmetry.…

Strongly Correlated Electrons · Physics 2014-03-19 Emilie Fulton Huffman , Shailesh Chandrasekharan

We explore a novel and straightforward solution to the sign problem that has plagued the Auxiliary-field Monte Carlo (AFMC) method applied to many-body systems for more than a decade. We present a solution to the sign problem that has…

Nuclear Theory · Physics 2007-08-23 G. Stoitcheva , W. E. Ormand , D. Neuhauser , D. J. Dean

We explore the sign problem in strongly coupled lattice QED with one flavor of Wilson fermions in four dimensions using the fermion bag formulation. We construct rules to compute the weight of a fermion bag and show that even though the…

High Energy Physics - Lattice · Physics 2011-03-07 Shailesh Chandrasekharan , Anyi Li

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

The fermion sign problem, the biggest obstacle in quantum Monte Carlo calculations, is completely solved in this paper. Here, we find a strategy, in which the contribution from those negative-weighted paths is thoroughly cancelled or…

Computational Physics · Physics 2022-06-01 J. Wang , D. Y. Sun

In this paper, we discover a new quantum Monte Carlo (QMC) method to solve the fermion sign problem in interacting fermion models by employing Majorana representation of complex fermions. We call it "Majorana QMC" (MQMC). Especially, MQMC…

Strongly Correlated Electrons · Physics 2015-07-22 Zi-Xiang Li , Yi-Fan Jiang , Hong Yao

We present a new approach for Monte Carlo simulations of lattice quantum spin systems which is able to eliminate the negative sign problem. Its complexity is linear in the volume of the lattice. Its efficiency is tested on a simple…

High Energy Physics - Lattice · Physics 2008-02-03 A. Galli

Motivated by the fermion bag approach we construct a new class of Hamiltonian lattice field theories that can help us to study fermionic quantum critical points, particularly those with four-fermion interactions. Although these theories are…

Strongly Correlated Electrons · Physics 2020-04-03 Emilie Huffman , Shailesh Chandrasekharan

We review a recently proposed approach to the problem of alternating signs for fermionic many body Monte Carlo simulations in finite temperature simulations. We derive an estimate for fermion wandering lengths and introduce the notion of…

High Energy Physics - Lattice · Physics 2009-11-07 Dean Lee

A new approach to formulate the fermion field on lattice is introduced by proposing a new Dirac operator on lattice.This approach can eliminate the Fermion doubling problem, preserve the chiral symmetry and get the same dispersion relation…

High Energy Physics - Lattice · Physics 2007-05-23 Bo Feng , Jianming Li , Xingchang Song

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
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