WloopPHI: A tool for ab initio characterization of Weyl semimetals

TL;DR

WloopPHI is a Python tool that extends WIEN2k to compute and characterize Weyl semimetals by calculating their chirality and topological features using advanced theoretical methods.

Contribution

It introduces a novel computational approach for ab initio characterization of Weyl semimetals, integrating Wilson loop and Berry phase techniques.

Findings

Validated on TaAs with experimental agreement

Identified Weyl points and nodal lines in YRh6Ge4

Mapped chiralities of topological features

Abstract

WloopPHI is a Python code that expands the features of WIEN2k, a full-potential all-electron density functional theory package, by the characterization of Weyl semimetals. It enables the calculation of the chirality (or "monopole charge") associated with Weyl nodes and nodal lines. The theoretical methodology for the calculation of the chirality is based on an extended Wilson loop method and a Berry phase approach. We validate the code using TaAs, which is a well-characterized Weyl semimetal, both theoretically and experimentally. Afterwards, we applied the method to the characterization of YRh$_6$Ge$_4$ and found two sets of Weyl points (ca. 0.2 eV below the Fermi energy) together with a topological nodal line (protected by mirror symmetry) crossing the Fermi energy and mapped their chiralities.