Rotating vortex core: An instrument for detecting core excitations

Effects of fermion zero modes (bound states in a vortex core) on the rotational dynamics of vortices with spontaneously broken axisymmetry are considered. The results are compared with the Helsinki NMR experiments where the vortex cores were driven to a fast rotation and torsional oscillations by an NMR rf field. We predict a resonance NMR absorption on localized states at the external frequency comparable with the interlevel distance which is similar to the cyclotron Landau damping. The resonances can resolve the localized levels in vortex cores. For a pure rotation of the core, the effect depends on the relative signs of the vortex winding and of the core rotation; thus it is sensitive to the direction of rotation of the container. The similarity with fermion zero modes on fundamental strings, which simulate the thermodynamics of black holes, is discussed.