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Related papers: Preempting Fermion Sign Problem: Unveiling Quantum…

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We study phase transitions driven by fermionic double-trace deformations in gauge-gravity duality. Both the strength of the double trace deformation and the infrared conformal dimension/self-energy scaling of the quasiparticle can be used…

High Energy Physics - Theory · Physics 2015-11-04 E. Gubankova , M. Cubrovic , J. Zaanen

We perform large-scale quantum Monte Carlo simulations of SLAC fermions on a two-dimensional square lattice at half filling with a single Dirac cone with $N=2$ spinor components and repulsive on-site interactions. Despite the presence of a…

Strongly Correlated Electrons · Physics 2022-06-27 S. Mojtaba Tabatabaei , Amir-Reza Negari , Joseph Maciejko , Abolhassan Vaezi

Here we develop a new scheme of projective quantum Monte-Carlo (QMC) simulation combining unbiased zero-temperature (projective) determinant QMC and variational Monte-Carlo based on Gutzwiller projection wave function, dubbed as…

Strongly Correlated Electrons · Physics 2026-04-08 Wei-Xuan Chang , Zi-Xiang Li

Ground state properties of the Hubbard model are of fundamental importance to understand the mechanism of unconventional superconductivity in the high-T_c cuprates and other materials. One of the most powerful numerical methods for strongly…

Strongly Correlated Electrons · Physics 2026-03-30 Jodie Roberts , Beau A. Thompson , R. Torsten Clay

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 fermion-sign problem at finite density is a persisting challenge for Monte-Carlo simulations. Theories that do not have a sign problem can provide valuable guidance and insight for physically more relevant ones that do. Replacing the…

High Energy Physics - Lattice · Physics 2013-01-10 Axel Maas , Lorenz von Smekal , Björn Wellegehausen , Andreas Wipf

We explore different ways of incorporating accurate trial wave functions into free projection auxiliary field quantum Monte Carlo (fp-AFQMC). Trial states employed include coupled cluster singles and doubles, multi-Slater, and symmetry…

Chemical Physics · Physics 2021-04-15 Ankit Mahajan , Sandeep Sharma

We present a method for performing path integral molecular dynamics (PIMD) simulations for fermions and address its sign problem. PIMD simulations are widely used for studying many-body quantum systems at thermal equilibrium. However, they…

Chemical Physics · Physics 2020-05-07 Barak Hirshberg , Michele Invernizzi , Michele Parrinello

Quantum annealing is a generic solver of the optimization problem that uses fictitious quantum fluctuation. Its simulation in classical computing is often performed using the quantum Monte Carlo simulation via the Suzuki--Trotter…

Quantum Physics · Physics 2016-12-15 Masayuki Ohzeki

The fluctuations of massless Dirac fermion can not only turn a first-order bosonic phase transition (in the Landau sense) to a quantum critical point, but also work reversely to enhance the first-order transition itself, depending on the…

Strongly Correlated Electrons · Physics 2021-03-03 Yuzhi Liu , Zi Yang Meng , Shuai Yin

I review recent developments in determining the QCD phase diagram by means of lattice simulations. Since the invention of methods to side-step the sign problem a few years ago, a number of additional variants have been proposed, and…

High Energy Physics - Lattice · Physics 2007-05-23 Owe Philipsen

It is believed that not all quantum systems can be simulated efficiently using classical computational resources. This notion is supported by the fact that in quantum Monte Carlo (QMC) simulations for a large number of important problems it…

Strongly Correlated Electrons · Physics 2017-04-14 Z. Ringel , D. L. Kovrizhin

In this work, within the framework of path integral Monte Carlo, we construct a pseudo-fermion propagator by replacing the original fermionic determinant with its absolute value. This modified propagator defines an auxiliary system free…

Computational Physics · Physics 2026-03-31 Yunuo Xiong , Hongwei Xiong

The coupling between fermionic matter and gauge fields plays a fundamental role in our understanding of nature, while at the same time posing a challenging problem for theoretical modeling. In this situation, controlled information can be…

Strongly Correlated Electrons · Physics 2020-06-05 Lukas Janssen , Wei Wang , Michael M. Scherer , Zi Yang Meng , Xiao Yan Xu

Topology plays a cardinal role in explaining phases and quantum phase transitions beyond the Landau-Ginzburg-Wilson paradigm. In this study, we formulate a set of models of Dirac fermions in 2+1 dimensions with…

Strongly Correlated Electrons · Physics 2025-07-15 Gabriel Rein , Marcin Raczkowski , Zhenjiu Wang , Toshihiro Sato , Fakher F. Assaad

A possible solution of the notorious sign problem preventing direct Monte Carlo calculations for systems with non-zero chemical potential is to deform the integration region in the complex plane to a Lefschetz thimble. We investigate this…

High Energy Physics - Lattice · Physics 2016-01-27 Andrei Alexandru , Gokce Basar , Paulo Bedaque

Quantum Monte Carlo simulations provide one of the more powerful and versatile numerical approaches to condensed matter systems. However, their application to frustrated quantum spin models, in all relevant temperature regimes, is hamstrung…

Strongly Correlated Electrons · Physics 2017-07-20 Stefan Wessel , B. Normand , Frédéric Mila , Andreas Honecker

Progress in the understanding of quantum critical properties of itinerant electrons has been hindered by the lack of effective models which are amenable to controlled analytical and numerically exact calculations. Here we establish that the…

Disordered Systems and Neural Networks · Physics 2016-02-02 J. H. Pixley , Pallab Goswami , S. Das Sarma

We study theoretically the quantum critical phenomenon of the phase transition between the trivial insulator and the topological insulator in (3+1) dimensions, which is described by a Dirac fermion coupled to the electromagnetic field. The…

Mesoscale and Nanoscale Physics · Physics 2012-11-01 Hiroki Isobe , Naoto Nagaosa

We investigate the QCD phase diagram in the strong coupling limit by using a newly developed auxiliary field Monte-Carlo (AFMC) method. Starting from an effective action in the leading order of the 1/g^2 and 1/d expansion with one species…

High Energy Physics - Lattice · Physics 2012-11-13 Akira Ohnishi , Terukazu Ichihara , Takashi Z. Nakano