Fig. 2: Continuous-wave excitation at a frequency of fex = 101.5 MHz and a current density of j = 1.7 × 1011 A m−2.
From: Few-nm tracking of current-driven magnetic vortex orbits using ultrafast Lorentz microscopy
a Four time-resolved Lorentz micrographs acquired in time steps of 2.5 ns at a defocus of 520 μm (scale bar: 1 μm). b Line profiles at the position of the vortex core along the x-direction, closely resembling a sinusoidal displacement. White: Best fit of a harmonic oscillator model (scale bar: 300 nm). (b, Inset) Blue: Example of a single line profile at t = 0.1 ps. Red: Fitted Lorentzian line shape. c Red: Mean vortex core position determined from set of eight identical Lorentz micrographs at each delay t. Blue: Best fit of the harmonic oscillator model (scale bar: 100 nm). d Example of the spatial spread of the tracked vortex position (scale bar: 20 nm). e Distribution of the spatial deviation from the mean for all position measurements in x- and y-direction.
