Acoustic-Wave-Induced Magnetization Switching of Magnetostrictive Nanomagnets from Single-Domain to Nonvolatile Vortex States

We report experimental manipulation of the magnetic states of elliptical cobalt magnetostrictive nanomagnets (with nominal dimensions of similar to 340 nm X 270 nm.,X 12 nm) delineated on bulk 128 degrees Y-cut lithium niobate with acoustic waves (AWs) launched,from interdigitated electrodes. Isolated nanomagnets (no dipole interaction with any other nano magnet) that are:initially magnetized with a magnetic field to a single-domain state with the magnetization aligned along the,. major axis of the ellipse are driven into a vortex state by acoustic waves that modulate the stress anisotropy of these nanomagnets. The nanomagnets remain in the vortex state until they are reset by a strong magnetic field to:the initial single-domain state, making the vortex state nonvolatile. This phenomenon is modeled and explained using a micromagnetic framework and could lead to the, development, of extremely energy efficient magnetization switching methodologies for low-power computing applications.