English
Related papers

Related papers: Preempting Fermion Sign Problem: Unveiling Quantum…

200 papers

We propose a projection approach to perform quantum Monte Carlo (QMC) simulation on the infinite-$U$ Hubbard model at some integer fillings where either it is sign problem free or surprisingly has an algebraic sign structure -- a power law…

Strongly Correlated Electrons · Physics 2021-12-28 Yunqing Ouyang , Xiao Yan Xu

We investigate a quantum criticality of an antiferromagnetic phase transition in the Hubbard model on a square lattice with a $d$-wave pairing field by large-scale auxiliary-field quantum Monte Carlo simulations. Since the $d$-wave pairing…

Strongly Correlated Electrons · Physics 2022-04-04 Yuichi Otsuka , Kazuhiro Seki , Sandro Sorella , Seiji Yunoki

Quantum electrodynamics in 2+1 dimensions is an effective gauge theory for the so called algebraic quantum liquids. A new type of such a liquid, the algebraic charge liquid, has been proposed recently in the context of deconfined quantum…

Strongly Correlated Electrons · Physics 2008-05-06 Flavio S. Nogueira

Nowadays the term 'sign problem' is used to identify two different problems. The ideas to overcome the first type of the 'sign problem' of strongly oscillating complex valued imtegrand in the Feynman path integrals comes from…

Statistical Mechanics · Physics 2020-03-04 Vladimir Filinov , Alexander Larkin

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

Numerical simulations of strongly correlated electron systems suffer from the notorious fermion sign problem which has prevented progress in understanding if systems like the Hubbard model display high-temperature superconductivity. Here we…

Strongly Correlated Electrons · Physics 2015-06-24 S. Chandrasekharan , J. Cox , J. C. Osborn , U. -J. Wiese

Quantum critical systems offer promising advancements in quantum sensing and metrology, yet face limitations like critical slowing down and a restricted criticality-enhanced region. Here, we introduce a critical sensing scheme that mitigate…

We investigate the magnetic quantum phase-transitions in bulk correlated metals at the level of dynamical mean-field theory. To this end, we focus on the Hubbard model on a simple cubic lattice as a function of temperature and electronic…

Strongly Correlated Electrons · Physics 2024-09-09 S. Adler , D. R. Fus , M. O. Malcolms , A. Vock , K. Held , A. A. Katanin , T. Schäfer , A. Toschi

Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. Heavy fermion metals have in recent years emerged as prototypical systems to study quantum critical points.…

Strongly Correlated Electrons · Physics 2009-05-24 Philipp Gegenwart , Qimiao Si , Frank Steglich

A key problem in the field of quantum criticality is to understand the nature of quantum phase transitions in systems of interacting itinerant fermions, motivated by experiments on a variety of strongly correlated materials. Much attention…

Strongly Correlated Electrons · Physics 2021-06-30 Rufus Boyack , Hennadii Yerzhakov , Joseph Maciejko

Quantum Monte Carlo (QMC) is an advanced simulation methodology for studies of manybody quantum systems. In this review, we focus on the electronic structure QMC, i.e., methods relevant for systems described by the electron-ion…

Other Condensed Matter · Physics 2010-08-16 Michal Bajdich , Lubos Mitas

The average phase factor of the QCD fermion determinant signals the strength of the QCD sign problem. We compute the average phase factor as a function of temperature and baryon chemical potential using a two-flavor NJL model. This allows…

High Energy Physics - Lattice · Physics 2010-01-22 Jens O. Andersen , Lars T. Kyllingstad , Kim Splittorff

The negative sign problem in quantum Monte Carlo (QMC) simulations of cluster impurity problems is the major bottleneck in cluster dynamical mean field calculations. In this paper we systematically investigate the dependence of the sign…

Strongly Correlated Electrons · Physics 2015-11-18 Hiroshi Shinaoka , Yusuke Nomura , Silke Biermann , Matthias Troyer , Philipp Werner

At sufficiently low temperatures, interacting electron systems tend to develop orders. Exceptions are quantum critical point (QCP) and quantum spin liquid (QSL), where fluctuations prevent the highly entangled quantum matter to an ordered…

Strongly Correlated Electrons · Physics 2022-09-30 Yuan Da Liao , Xiao Yan Xu , Zi Yang Meng , Yang Qi

The severity of the sign problem in lattice QCD at nonzero baryon density is measured by the average phase of the fermion determinant. Motivated by the equivalence of chiral random matrix theory and QCD to leading order in the epsilon…

High Energy Physics - Lattice · Physics 2010-11-05 Jacques Bloch , Tilo Wettig

Many fascinating systems suffer from a severe (complex action) sign problem preventing us from calculating them with Markov Chain Monte Carlo simulations. One promising method to alleviate the sign problem is the transformation of the…

Strongly Correlated Electrons · Physics 2022-11-18 Marcel Rodekamp , Christoph Gäntgen

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

The sign problem is one of the central obstacles to efficiently simulating quantum many-body systems. It is commonly believed that some phases of matter, such as the double semion model, have an intrinsic sign problem and can never be…

Strongly Correlated Electrons · Physics 2026-05-11 Leyna Shackleton

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 simulation of strongly correlated fermionic systems remains one of the most significant challenges in computational physics due to the exponential growth of the Hilbert space and the fermionic sign problem. In this work, we present a…

Quantum Physics · Physics 2026-02-18 Hugo Catala , Ezequiel Valero , German Rodrigo