Controllable Weyl nodes and Fermi arcs in a light-irradiated carbon allotrope

TL;DR

This study demonstrates how linearly polarized light can precisely control the positions of Weyl nodes and Fermi arcs in a carbon allotrope, offering a new way to manipulate topological states in materials.

Contribution

It introduces a method to control Weyl physics in a carbon allotrope using light, combining first-principles calculations with Floquet theory to achieve tunable topological features.

Findings

Weyl nodes and Fermi arcs can be accurately manipulated by light intensity.

Symmetry considerations restrict Weyl node movement to high-symmetry planes.

Light irradiation preserves certain symmetries, enabling controlled topological states.

Abstract

The precise control of Weyl physics in realistic materials oers a promising avenue to construct accessible topological quantum systems, and thus draw widespread attention in condensed-matter physics. Here, based on rst-principles calculations, maximally localized Wannier functions based tight-binding model, and Floquet theorem, we study the light-manipulated evolution of Weyl physics in a carbon allotrope C6 crystallizing a face-centered orthogonal structure (fco-C6), an ideal Weyl semimetal with two pairs of Weyl nodes, under the irradiation of a linearly polarized light (LPL). We show that the positions of Weyl nodes and Fermi arcs can be accurately controlled by changing light intensity. Moreover, we employ a low-energy eective k p model to understand light-controllable Weyl physics. The results indicate that the symmetry of light-irradiated fco-C6 can be selectively preserved, which guarantees that the light-manipulated Weyl nodes can only move in the highsymmetry plane in momentum space. Our work not only demonstrates the ecacy of employing periodic driving light elds as an ecient approach to manipulate Weyl physics, but also paves a reliable pathway for designing accessible topological states under light irradiation.