Imaging of Magnetic Excitations in Nanostructures with Near-Field Microwave Microscopy

Abstract We present images of spin-wave excitations in a patterned yttrium iron garnet (YIG) thin film obtained by use of near-field microwave microscopy, which can achieve spatial resolution as high as 50 nm. Visualization of magnetic excitations is an enticing prospect for high-speed, high-density magnetic logic and storage applications. This has spurred the development of new magnetic microscopy and imaging techniques in recent years. Here we present a novel approach for local imaging of magnetic modes excited at room temperature with sub-diffraction-limited spatial resolution. This approach is based on a special atomic force microscope with broadband GHz capability for imaging the spatial distribution of dynamic magnetic excitations in patterned magnetic structures. Due to the inherent sub-wavelength, nanometer-scale spatial resolution of near-field scanning probe techniques, this approach has potential for a significant improvement in spatial resolution over optical techniques.