Abstract: The light-driven control of quantum materials is rapidly evolving into new stages with advances in more stable and powerful lasers. In this talk, we will present two optical driving protocols for guided material control: resonant excitation of collective modes and coherent off-resonant driving.
In the first part, we investigate the photoinduced dynamics of the soft magnet Sr3Ir2O7 — a system near a quantum critical point and recently proposed as an antiferromagnetic excitonic insulator — to determine its ground state and magnon dynamics. Upon photodoping, the magnon exhibits a dynamic energy blueshift, suggesting a non-thermal pathway for tuning electronic interactions.
In the second part, we explore Floquet engineering under periodic driving as a deterministic and reversible method for controlling correlated materials. We demonstrate how the driven dynamics on sub-cycle timescales — dubbed Floquet micromotion — manifest as a coherent electronic Raman continuum. The micromotion can also be manipulated to selectively break symmetries and interact with magnetic ordering in the low-frequency limit, suggesting new opportunities for micromotion-based material engineering. Broader insights into the light-driven control of correlated materials will also be discussed.