Extensively parallelizable chiral fermion

TL;DR

This paper introduces a highly parallelizable method for implementing chiral fermions using the overlap-Dirac operator, leveraging a contour-integral approach and the Sakurai-Sugiura inspired projection, suitable for modern multi-core and GPGPU systems.

Contribution

It presents a novel, scalable approach to realize the overlap-Dirac operator without low mode calculations, enhancing computational efficiency in chiral fermion simulations.

Findings

Method achieves sufficient chiral symmetry in double precision.

The proposed approach demonstrates strong parallel scaling.

It effectively utilizes multi-core and GPGPU architectures.

Abstract

Chiral symmetry is a key to investigating quantum physics, from condensed matter to particle physics. We propose a novel way of realizing a chiral fermion, known as the overlap-Dirac operator, without explicitly calculating the low modes of the Wilson-Dirac operator. We introduce a projection operator inspired by the Sakurai-Sugiura method and formulate the exact sign function and overlap-Dirac operator with a contour-integral form. Like the Sakurai-Sugiura method, the proposing method is multi-scale parallelizable, which fits the multi-core/multi-GPGPU paradigm. We confirm that the quality of chiral symmetry realized with the proposed method is sufficient for double precision. We evaluate the strong scaling of the proposing method.