Tailoring Spin-Wave Channels in an Artificial Spin Ice

Artificial spin ices are ensembles of geometrically arranged interacting nanomagnets that have shown promising potential for the realization of reconfigurable magnonic crystals. Such systems allow for the manipulation of spin waves on the nanoscale and their potential use as information carriers. However, there are presently two general obstacles to the realization of artificial spin-ice-based magnonic crystals: the magnetic state of artificial spin ices is difficult to reconfigure and the magnetostatic interactions between the nanoislands are often weak, preventing mode coupling.

In this work, published in Physical Review Applied, researchers from Northumbria University, the Paul Scherrer Institute and Argonne National Laboratory have demonstrated through micromagnetic modeling that coupling a reconfigurable artificial spin-ice geometry made of weakly interacting nanomagnets to a soft magnetic underlayer creates a complex system exhibiting dynamically coupled modes. These give rise to spin-wave channels in the underlayer at well-defined frequencies, based on the artificial spin-ice magnetic state.  Because the magnetic state of the artificial spin ice can be deterministically reconfigured,  it is possible to turn 'on' and 'off' these spin wave channels. 

These findings open the door to the realization of reconfigurable magnonic crystals with potential applications for data transport and processing in magnonic-based logic architectures. These could enable simultaneous waveguiding and data processing through time-dependent spin- wave channel reconfiguration, enabling alternative schemes for computing using artificial spin ices.