Magnetic skyrmion resonance with density control

Magnetic skyrmions are a candidate for next-generation spintronic devices. Their topological nature makes them robust, allowing for a non-volatile, high-speed, and low-power-consumption method of storing and processing information. In addition, recent advances in skyrmionics have demonstrated both electrical and thermal techniques for controlling skyrmion densities in thin films. In this talk we present measurements of magnetic resonance in ferromagnetic multilayers with interfacial Dzyaloshinskii-Moriya interaction. We have performed room temperature experiments utilizing both conventional field-driven ferromagnetic resonance and spin-torque ferromagnetic resonance. We find a difference in the resonance readout between the phases with and without skyrmions, indicating a resonance readout of skyrmions themselves. This observation is further supported by micromagnetic simulations and Lorentz transmission electron microscopy with spatial resolution on the order of a few nanometers, where we directly observe skyrmions in our thin films.