LAUSR

The Floquet state, which is a periodically and intensely light-driven quantum state in solids, has been attracting attention as a novel state that is coherently controllable on an ultrafast time scale. An important issue has been to demonstrate experimentally novel electronic properties in the Floquet state. One technique is light scattering spectroscopy, which offers an important clue to clarifying the symmetries and energy structures of the states through symmetry analysis of the polarization selection rules. Here, we determine circular and linear polarization selection rules of light scattering in a mid-infrared-driven Floquet system in monolayer MoS 2 and provide a comprehensive understanding in terms of the “dynamical symmetry” of the Floquet state. Floquet engineering describes the control of a quantum system using light-matter interactions and has received renewed interest due to recent developments in ultrafast spectroscopy techniques. Here, the authors use light scattering spectroscopy to investigate the Floquet state in MoS 2 and apply dynamical symmetries to understand the polarisation selection rules