Modification of the Weyl semimetal states in the topological insulator superlattice by light fields

Abstract

Weyl semimetals exhibit extraordinary electronic properties derived from their topologically protected Weyl nodes. However, their practical applications are constrained by the scarcity of natural materials and the inherent lack of tunability in their intrinsic properties. In this work, we investigate how the topological states of Weyl semimetals in artificial heterostructures composed of alternating layers of topological insulators and normal insulators can be dynamically regulated by an external alternating-current light field. To this end, we construct a lattice regularization of the continuum multilayer model, which enables a systematic analysis of light-induced Weyl semimetal phases. Based on the model, the Floquet–Weyl semimetal states can be investigated for both longitudinal and transverse light field. It is found that the field provides flexible controllability on the topological phase transition and exhibits the precise manipulation on Weyl nodes, including adjustments to their energy positions, chirality reversal, node annihilation or creation, and anisotropic deformation. The field-driven modification overcomes the rigidity of natural Weyl materials and paves the way for their applications in tunable optoelectronics and quantum computing.