High-frequency spin wave modes excited by strain pulse in vortex state magnetostrictive nanomagnets

Using micromagnetic simulations, we find that the high frequency spin wave modes of vortexes in circular magnetostrictive nanomagnets can be excited by in-plane strain pulses, which are quite distinct from the spin wave modes excited by magnetic field pulses. The spectrum and spatial distribution of spin wave modes are obtained as a function of the diameter (D) and thickness (L) of nanomagnets. Our results show that the increase in diameter leads to a redshift of the frequencies of spin wave modes. Furthermore, we investigate the impact of ring shape impurities on the high frequency spin wave modes, and it is found that both the type and position of impurities can be used to tailor the strain induced spin wave spectroscopy of magnetic vortexes. Our findings provide meaningful guidelines for the further study of strain-mediated sub-nanosecond magnetization dynamics, which may obviously improve the operating frequency of straintronic devices.