Comprehensive scan for nonmagnetic Weyl semimetals with nonlinear optical response

TL;DR

This paper develops an algorithm to identify nonmagnetic Weyl semimetals with Weyl points near the Fermi level, creating a new database and analyzing their nonlinear optical responses, including giant shift currents.

Contribution

An efficient algorithm was created to automatically find Weyl points in nonmagnetic materials, enabling the construction of a comprehensive Weyl semimetal database.

Findings

Discovered 46 nonmagnetic Weyl semimetals near the Fermi level.

Identified 9 chiral structures potentially hosting quantized circular photogalvanic effect.

Explored giant shift current in nonlinear optical response.

Abstract

As the development of topological band theory, comprehensive databases about time reversal and crystalline symmetries protected nonmagnetic topological materials were developed via first-principles calculations recently. However, owing to the low symmetry requirement of Weyl points, the symmetry-based topological indicator cannot be applied to Weyl semimetals (WSMs). Hitherto, the WSMs with Weyl points in arbitrary positions are still absent in the well-known databases. In this work, we develop an efficient algorithm to search for Weyl points automatically and establish a database of nonmagnetic WSMs with Weyl points near Fermi level based on the total experimental noncentrosymmetric crystal structures in the Inorganic Crystal Structure Database (ICSD). Totally 46 Weyl semimetals were discovered to have nearly clean Fermi surface and Weyl points near Fermi level within 300 meV, and 9 of them are chiral structures which may host the quantized circular photogalvanic effect. In addition, the nonlinear optical response is studied and giant shift current is explored in the end. Besides nonmagnetic WSMs, our powerful tools can also be used in the discovery of magnetic topological materials.