Bicircular Light Floquet Engineering of Magnetic Symmetry and Topology and Its Application to the Dirac Semimetal Cd3As2

We show that bicircular light (BCL) is a versatile way to control magnetic symmetries and topology in materials. The electric field of BCL, which is a superposition of two circularly polarized light waves with frequencies that are integer multiples of each other, traces out a rose pattern in the polarization plane that can be chosen to break selective symmetries, including spatial inversion. Using a realistic low-energy model, we theoretically demonstrate that the three-dimensional Dirac semimetal Cd3As2 is a promising platform for BCL Floquet engineering. Without strain, BCL irradiation induces a transition to a noncentrosymmetric magnetic Weyl semimetal phase with tunable energy separation between the Weyl nodes. In the presence of strain, we predict the emergence of a magnetic topological crystalline insulator with exotic unpinned surface Dirac states that are protected by a combination of twofold rotation and time reversal (2') and can be controlled by light.

Automated summary

Bicircular light is shown to be a versatile method for controlling magnetic symmetries and topology in materials. Using a low-energy model, Cd3As2 is theoretically demonstrated as a promising platform for BCL Floquet engineering, which can induce a transition to a noncentrosymmetric magnetic Weyl semimetal phase. With strain, a magnetic topological crystalline insulator with unique unpinned surface Dirac states can be predicted, protected by a combination of twofold rotation and time reversal symmetries and controllable by light.