We are passionate about understanding interactions between the quantum degrees of freedom in solid-state systems such as electron spins, photons, and magnons. We investigate their couplings, propagations, and non-equilibrium dynamics, and explore new device concepts for spin-based quantum information processing. Our experimental toolkits include ultrafast optical microscopy, Sagnac interferometry, microwave and precision measurements, as well as time-resolved X-ray and angle-resolved photoelectron spectroscopy at external facilities.