Tuning interactions in reconfigurable kagome artificial spin ices for magnonics

Abstract

We report broadband spin-wave spectroscopy on kagome artificial spin ices (KASIs) made of large arrays of disconnected Ni81Fe19 400-nm-long nanobars. We observed spin wave spectra that varied characteristically upon the separation between neighboring nanobars. The dipolar coupling within the KASI is analyzed in terms of a configuration-dependent bias field. It varies between about 30 and 40 mT for nearest-neighbor separations of 300 and 60 nm, respectively. Similarly to interconnected KASIs, we reprogram the spin wave spectra by means of a specific field protocol. The disconnected KASIs are promising for reprogramable spin wave guiding in underlayers.