Magnetization Dynamics of Topological Defects and the Spin Solid in   Kagome Artificial Spin Ice
  We report broadband spin-wave spectroscopy on kagome artificial spin ice (ASI) made of large arrays of interconnected Ni$_{80}$Fe$_{20}$ nanobars. Spectra taken in saturated and disordered states exhibit a series of resonances with characteristic magnetic field dependencies. Making use of micromagnetic simulations, we identify resonances that reflect the spin-solid-state and monopole-antimonopole pairs on Dirac strings. The latter resonances allow for the generation of highly-charged vertices in ASIs via microwave assisted switching. Our findings open further perspectives for fundamental studies on ASIs and their usage in reprogrammable magnonics. 
V. S. Bhat, F. Heimbach, I. Stasinopoulos, D. Grundler
cond-mat.mes-hall