All-Dielectric Metaphotonics for Advanced THz Control of Spins

While THz pulses with durations close to a single oscillation period are widely regarded as optimal stimuli for achieving the fastest and most energy-efficient control of spins in magnetic materials, all-dielectric metasurfaces have recently been demonstrated to provide the least dissipative platform for enhancing and controlling light-spin coupling. All-dielectric metasurfaces for the THz control of spins hold great potential in the field of spintronics and related technologies, pushing the boundaries of speed and energy efficiency in spin-based information processing. Here, we introduce and demonstrate a novel material: a specially designed dielectric metasurface for an advanced THz control of spins in a ferrimagnetic film of iron garnet. By structuring a nonmagnetic substrate, one can force a THz electromagnetic field, otherwise described by plane waves, to acquire an out-of-plane magnetic field and thus enable arbitrary direction of the torque acting on spins in all three dimensions. Hence, metaphotonics opens up a plethora of opportunities for advanced control of spins at THz rates in many hot fields of contemporary science, including spintronics, magnonics, and quantum computing.