Spin-torque skyrmion resonance in a frustrated magnet induced by spin-polarized currents

Skyrmions offer potential for ultra-dense magnetic data storage, typically stabilized by Dzyaloshinskii-Moriya interaction (DMI). Recently, magnetic frustration was shown to stabilize Skyrmions without DMI, as observed in Fe₃Sn₂ crystals, where they persist above room temperature and respond to electrical currents. We introduce a technique to study Skyrmion ferromagnetic resonance (FMR) in bulk Fe₃Sn₂ using AC spin torque and time-resolved optical probing. We resolve counter-clockwise and breathing modes and track magnetic phase transitions. Simulations via OOMMF confirm a transition from a disordered state to a stripe phase, and ultimately to a uniform Skyrmion crystal lattice. Applying a DC current modulates the Skyrmion resonance linewidth, attributed to damping-like spin-orbit torque as supported by micromagnetic simulations. We extract an effective spin Hall conductivity of ~793 &plusmn; 176 (<i>&hstrok;</i>/e)(&Omega; cm)^-1. Planar Hall measurements reveal real-space spin texture contributions, highlighting prospects for Skyrmion-based spin current sensing.