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Related papers: Low-lying Dirac eigenmodes and monopoles in 4D com…

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The low energy eigenmodes of the continuum QCD Dirac operator are extended, but on the lattice, due to discretization effects, the Dirac operator can have localized eigenmodes. These non-physical modes can introduce strong lattice artifacts…

High Energy Physics - Lattice · Physics 2009-04-14 Anna Hasenfratz , Roland Hoffmann , Stefan Schaefer

The lowest eigenmodes of the Dirac operator are related to the dynamical breaking of the chiral symmetry in Quantum Chromodynamics (QCD). In our work we construct quark propagators which exclude a varying number of the lowest Dirac…

High Energy Physics - Lattice · Physics 2011-11-22 C. B. Lang , Mario Schröck

The spontaneous breaking of chiral symmetry in QCD is known to be linked to a non-zero density of eigenvalues of the massless Dirac operator near the origin. Numerical studies of two-flavour QCD now suggest that the low quark modes are…

High Energy Physics - Lattice · Physics 2008-11-26 Martin Lüscher

We study the global symmetries of naive lattices Dirac operators in QCD-like theories in any dimension larger than two. In particular we investigate how the chosen number of lattice sites in each direction affects the global symmetries of…

High Energy Physics - Lattice · Physics 2017-08-09 Mario Kieburg , Tim R. Würfel

At low temperature in the epsilon regime of QCD the low-end of the Dirac spectrum is described by random matrix theory. In contrast, there has been no similarly well established staistical description in the high temperature, chirally…

High Energy Physics - Lattice · Physics 2010-11-16 Tamas G. Kovacs , Ferenc Pittler

We apply different types of overlap operators in quenched QCD simulations to compute the zero mode contribution to the pseudo-scalar correlator. In particular we use the conventional Neuberger Dirac operator and the overlap hypercube Dirac…

High Energy Physics - Lattice · Physics 2007-05-23 S. Shcheredin , W. Bietenholz

We study two-dimensional (2D) Dirac fermions in the presence of a periodic mass term alternating between positive and negative values along one direction. This scenario could be realized for a graphene monolayer or for the surface states of…

Mesoscale and Nanoscale Physics · Physics 2023-06-29 A. De Martino , L. Dell'Anna , L. Handt , A. Miserocchi , R. Egger

We compute the chiral condensate in 2+1-flavor QCD through the spectrum of low-lying eigenmodes of Dirac operator. The number of eigenvalues of the Dirac operator is evaluated using a stochastic method with an eigenvalue filtering technique…

High Energy Physics - Lattice · Physics 2016-08-22 Guido Cossu , Hidenori Fukaya , Shoji Hashimoto , Takashi Kaneko , Jun-Ichi Noaki

We study the finite temperature localization transition in the spectrum of the overlap Dirac operator. Simulating the quenched approximation of QCD, we calculate the mobility edge, separating localized and delocalized modes in the spectrum.…

High Energy Physics - Lattice · Physics 2020-09-28 Reka A. Vig , Tamas G. Kovacs

Using the Dirac-mode expansion method, which keeps the gauge invariance, we analyze the Polyakov loop in terms of the Dirac modes in SU(3) quenched lattice QCD in both confined and deconfined phases. First, to investigate the direct…

High Energy Physics - Lattice · Physics 2014-03-24 Takumi Iritani , Hideo Suganuma

We study the problems of chiral symmetry breaking and eigenmode localisation in finite-temperature QCD by looking at the lattice Dirac operator as a random Hamiltonian. We recast the staggered Dirac operator into an unconventional…

High Energy Physics - Lattice · Physics 2016-06-29 Matteo Giordano , Tamas G. Kovacs , Ferenc Pittler

We present a quenched calculation of meson correlators with the overlap fermion at very small masses 2.6--13 MeV. In this region the pion Compton wavelength is larger than our lattice size L\simeq 1.23fm and the system is in the so-called…

High Energy Physics - Lattice · Physics 2009-11-11 Hidenori Fukaya , Shoji Hashimoto , Kenji Ogawa

We study the isoscalar and isovector $J=0,1$ mesons with the overlap operator within two flavour lattice QCD. After subtraction of the lowest-lying Dirac eigenmodes from the valence quark propagator all disconnected contributions vanish and…

High Energy Physics - Lattice · Physics 2015-04-16 M. Denissenya , L. Ya. Glozman , C. B. Lang

The low-lying Dirac modes become localised at the finite-temperature transition in QCD and in other gauge theories, suggesting a general connection between their localisation and deconfinement. The simplest model where this connection can…

High Energy Physics - Lattice · Physics 2021-10-29 György Baranka , Matteo Giordano

The stability of the Dirac spin-liquid on two-dimensional lattices has long been debated. It was recently demonstrated [Nature Commun. 10, 4254 (2019) and Phys. Rev. B 93, 144411 (2016)] that the staggered $\pi$-flux Dirac spin-liquid phase…

Strongly Correlated Electrons · Physics 2021-01-01 Santanu Dey

We compare eigenvalue correlations of the Dirac operator with a chemical potential obtained from lattice simulations of quenched QCD with analytic predictions obtained from chiral effective theories in the zero-momentum limit. By comparing…

High Energy Physics - Lattice · Physics 2008-11-26 James C. Osborn , Tilo Wettig

We study the embedded QCD monopoles (``quark monopoles'') using low-lying eigenmodes of the overlap Dirac operator in zero- and finite-temperature SU(2) Yang-Mills theory on the lattice. These monopoles correspond to the gauge-invariant…

High Energy Physics - Lattice · Physics 2007-05-23 M. N. Chernodub , S. M. Morozov

The low energy quasiparticle dispersion of various narrow gap and gapless semiconductors are respectively described by three dimensional massive and massless Dirac fermions. The three dimensional Dirac spinor structure admits a…

Mesoscale and Nanoscale Physics · Physics 2012-11-19 Pallab Goswami , Bitan Roy

The Dirac fermion with linear dispersion in the kagom\'e lattice governs the low-energy physics of different valleys at two inequivalent corners of hexagonal Brillouin zone. The effective Hamiltonian based on the cyclic permutation symmetry…

Strongly Correlated Electrons · Physics 2025-09-22 Xinyuan Zhou , Ziqiang Wang , Hua Chen

We discuss some properties of zero and near-zero modes of the Dirac operator, as observed in a recent simulation of 2-flavor QCD. The quarks have been implemented with the so-called Chirally Improved Dirac operator, which obeys the…

High Energy Physics - Lattice · Physics 2007-05-23 C. B. Lang , Pushan Majumdar , Wolfgang Ortner