Spectral fingerprinting: microstate readout via remanence ferromagnetic resonance in artificial spin ice

Abstract Artificial spin ices (ASIs) are magnetic metamaterials comprising geometrically tiled strongly-interacting nanomagnets. There is significant interest in these systems spanning the fundamental physics of many-body to potential applications neuromorphic computation, logic, and recently reconfigurable magnonics. Magnonics focused studies on ASI have date in-field GHz spin-wave response, convoluting effects from applied field, nanofabrication imperfections (‘quenched disorder’) microstate-dependent dipolar field landscapes. Here, we investigate zero-field measurements response demonstrate its ability provide a ‘spectral fingerprint’ system microstate. Removing allows deconvolution distinct contributions reversal dynamics spectra, directly measuring strength quenched disorder as well net magnetisation. We efficacy sensitivity this approach by three microstates with identical (zero) magnetisation, indistinguishable via magnetometry. The provides spectral fingerprints each state, allowing rapid, scaleable microstate readout. As artificial progress toward device implementation, functionality crucial minimize power consumption associated electromagnets. Several proposed hardware computation schemes hinge leveraging dynamic measurement perform for which fingerprinting solution.