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Related papers: Topological tunneling with Dynamical overlap fermi…

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Close to the continuum the lattice spacing affects the smallest eigenvalues of the Wilson Dirac operator in a very specific manner determined by the way in which the discretization breaks chiral symmetry. These effects can be computed…

High Energy Physics - Lattice · Physics 2012-11-09 K. Splittorff

We present simulation results for the 2-flavour Schwinger model with dynamical Ginsparg-Wilson fermions. Our Dirac operator is constructed by inserting an approximately chiral hypercube operator into the overlap formula, which yields the…

High Energy Physics - Lattice · Physics 2008-11-26 Jan Volkholz , Wolfgang Bietenholz , Stanislav Shcheredin

We construct new Ginsparg-Wilson fermions for QCD by inserting an approximately chiral Dirac operator - which involves ingredients of a perfect action - into the overlap formula. This accelerates the convergence of the overlap Dirac…

High Energy Physics - Lattice · Physics 2010-04-05 W. Bietenholz

The extreme computational costs of calculating the sign of the Wilson matrix within the overlap operator have so far prevented four dimensional dynamical overlap simulations on realistic lattice sizes, because the computational power…

High Energy Physics - Lattice · Physics 2008-12-18 N. Cundy , S. Krieg , G. Arnold , A. Frommer , Th. Lippert , K. Schilling

An old and apparently persistent problem in numerical lattice QCD is that the simulations tend to get trapped in a sector of fixed topological charge when the lattice spacing is taken to zero. The effect sets in very rapidly and may…

High Energy Physics - Lattice · Physics 2014-01-28 Martin Lüscher

Since the prediction and observation of topological Weyl semimetals (chiral TSMs), there have been enormous efforts to characterize further condensed matter realizations of chiral fermions. These efforts were dramatically accelerated by the…

Mesoscale and Nanoscale Physics · Physics 2025-12-24 Justin Schirmann , Adolfo G. Grushin , Benjamin J. Wieder

We discuss the potential of Ginsparg-Wilson fermion simulations in the epsilon-regime of chiral perturbation theory, regarding the determination of the leading low energy constants of the effective chiral Lagrangian. It turns out to be very…

High Energy Physics - Lattice · Physics 2009-11-10 K. -I. Nagai , W. Bietenholz , T. Chiarappa , K. Jansen , S. Shcheredin

We develop a theory of tunneling between two systems of spinless chiral fermions. This setup can be realized at the edge of a quantum Hall bilayer structure. We find that the differential conductance of such a device in the absence of…

Mesoscale and Nanoscale Physics · Physics 2024-04-30 D. B. Karki , K. A. Matveev

We present results from a 2+1 flavor DWF calculation at 1/a = 3 GeV and discuss strategies for similar calculations at finer lattice spacings which will target charm physics. At weak coupling the autocorrelation time of the global…

High Energy Physics - Lattice · Physics 2013-11-18 Greg McGlynn , Robert D. Mawhinney

We investigate how the topological charge density in lattice QCD simulations is affected by violations of chiral symmetry caused by the fermion action. To this end we compare lattice configurations generated with a number of different…

High Energy Physics - Lattice · Physics 2012-01-10 Falk Bruckmann , Nigel Cundy , Florian Gruber , Thomas Lippert , Andreas Schäfer

At stronger gauge-field couplings, the domain wall fermion (DWF) residual mass, a measure of chiral symmetry breaking, grows rapidly. This measure is largely due to near zero fermion eigenmodes of logarithm of the 4D transfer matrix along…

High Energy Physics - Lattice · Physics 2010-01-21 Dwight Renfrew , Thomas Blum , Norman Christ , Robert Mawhinney , Pavlos Vranas

We describe a new Hybrid Monte Carlo (HMC) algorithm for dynamical overlap fermions, which improves the rate of topological index changes by adding an additional (intensive) term to the action for the molecular dynamics part of the…

High Energy Physics - Lattice · Physics 2012-02-28 Nigel Cundy , Weonjong Lee

We show that the interplay between chiral tunneling and spin-momentum locking of helical surface states leads to spin amplification and filtering in a 3D Topological Insulator (TI). Chiral tunneling across a TI pn junction allows normally…

Mesoscale and Nanoscale Physics · Physics 2015-03-23 K. M. Masum Habib , Redwan N. Sajjad , Avik W. Ghosh

We present first results of classical-statistical real-time simulations of anomalous transport phenomena with overlap fermions. We find that even on small lattices overlap fermions reproduce the real-time anomaly equation with much better…

High Energy Physics - Lattice · Physics 2016-12-15 P. V. Buividovich , S. N. Valgushev

We investigate the eigenvalues of nearly chiral lattice Dirac operators constructed with five-dimensional implementations. Allowing small violation of the Ginsparg-Wilson relation, the HMC simulation is made much faster while the…

High Energy Physics - Lattice · Physics 2013-11-20 H. Fukaya , S. Aoki , G. Cossu , S. Hashimoto , T. Kaneko , J. Noaki

The tunneling of the massless Dirac fermions through a vector potential barrier are theoretically investigated, where the vector potential can be introduced by the very high and very thin (delta-function) magnetic potential barriers. We…

Mesoscale and Nanoscale Physics · Physics 2024-07-11 Z. D. Li , W. Zeng

Topological superfluid, new quantum matter that possesses gapless exotic excitations known as Majorana fermions, has attracted extensive attention recently. These excitations, which can encode topological qubits, could be crucial…

Quantum Gases · Physics 2016-01-18 Liang-Liang Wang , Wu-Ming Liu

Critical slowing down for the Krylov Dirac solver presents a major obstacle to further advances in lattice field theory as it approaches the continuum solution. We propose a new multi-grid approach for chiral fermions, applicable to both…

High Energy Physics - Lattice · Physics 2020-12-30 Richard C. Brower , M. A. Clark , Dean Howarth , Evan S. Weinberg

We study the transmission through single and double ferromagnetic barriers on the surface of a topological insulator. By adjusting the gate voltage and magnetization oreintation, the ferromagnetic barrier can be tuned into various…

Mesoscale and Nanoscale Physics · Physics 2009-09-03 Jinhua Gao , Wei-Qiang Chen , Xiao-Yong Feng , X. C. Xie , Fu-Chun Zhang

We test exact and approximate Ginsparg-Wilson fermions with respect to their chiral and scaling behavior in the 2-flavor Schwinger model. We first consider explicit approximate GW fermions in a short range, then we proceed to their chiral…

High Energy Physics - Lattice · Physics 2015-06-25 W. Bietenholz , I. Hip