Controllable Weyl Nodes and Fermi Arcs from Floquet Engineering Triple Fermions

TL;DR

This paper demonstrates how circularly polarized light can be used to controllably induce Weyl nodes and Fermi arcs in topological triple fermion materials like TiO, using Floquet engineering and first-principles calculations.

Contribution

It reveals a method to manipulate triple fermions into Weyl semimetals via Floquet engineering, breaking specific symmetries with light in realistic materials.

Findings

Circularly polarized light induces Weyl nodes in TiO.

Symmetry breaking by light enables controllable topological phase transitions.

Weyl nodes are located along high-symmetry lines or planes.

Abstract

Floquet engineering with periodic driving as a powerful tool for designing desirable topological states has been the subject of intense recent studies. Here, we present the application of Floquet engineering to investigate evolution of topological triple fermions under irradiation of circularly polarized light (CPL), a phenomenon that currently remains a mystery. By using first-principles calculations and Floquet theorem, we demonstrate that WC-type TiO and its analogues are promising candidates for Floquet engineering of triple fermions. The symmetry analysis reveals that the electric field of CPL can break the specific symmetries, such as the time-reversal symmetry and its combination of spatial symmetries, inducing a transition to a flexibly controllable Weyl semimetallic phase. The survived spatial symmetry, controlled by light, guarantees that the Weyl nodes are located along the high-symmetry line or in high-symmetry planes in momentum space. Our findings focusing on Floquet engineering in realistic materials featured by triple fermions would facilitate both theoretical and experimental interest.