Low-frequency and Moire-Floquet engineering: A review

We review recent work on low-frequency Floquet engineering and its application to quantum materials driven by light, focusing on van der Waals systems hosting Moire superlattices. These non-equilibrium systems combine the twist-angle sensitivity of the band structure with the flexibility of light drives. The frequency, amplitude, and polarization of light can be tuned in experimental setups, leading to platforms with on-demand properties. First, we review recent theoretical developments to derive effective Floquet Hamiltonians, emphasizing the low-frequency regime. We then review applications of some of these theories to study twisted graphene and transition metal dichalcogenide systems irradiated by light in free space and inside a waveguide. We study the changes induced in the quasienergies and steady-states, which can lead to topological transitions. Next, we consider van der Waals magnetic materials driven by low-frequency light pulses in resonance with the phonons. We discuss the phonon dynamics induced by the light and the resulting magnetic transitions from a Floquet perspective. We finish by outlining new directions for Moire-Floquet engineering in the low-frequency regime and their relevance for technological applications. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This review summarizes recent work on low-frequency Floquet engineering in quantum materials driven by light, with a focus on van der Waals systems hosting Moire superlattices. These non-equilibrium systems combine band structure sensitivity with drive flexibility, allowing for tuning of light frequency, amplitude, and polarization in experimental setups. Theoretical developments in deriving effective Floquet Hamiltonians are discussed, as well as applications to twisted graphene and transition metal dichalcogenide systems irradiated by light. Changes in quasienergies and steady-states induced by light can lead to topological transitions. Floquet engineering in the low-frequency regime for van der Waals magnetic materials and their relevance for technological applications are also explored.