Artificial spin ice (ASI) is a magnetic metamaterial comprised of interacting magnetic elements. The array's particular arrangement on the lattice leads to collective behaviour, often due to the frustrated interaction at the vertices leading to a highly degenerate state.

Minor loop driven return point memory in ASI is simulated using dipolar models, and subharmonic response is shown to occur in a specific regime of the parameter space. The minor loops' applied field strength and the lattice's quenched disorder and interaction strength are critical variables. A qualitative description of the origin of subharmonic behaviour is discussed and explored in square, Shakti and brickwork ASI geometries.

Symmetric and bicomponent square ASI systems' high-frequency dynamics are measured experimentally via ferromagnetic resonance (FMR). The bicomponent square artificial spin system is width-modified to allow global field control of specific microstates. These samples are measured using FMR to determine how the high-frequency response changes due to the microstate field landscape. The anticrossing gap in the prepared type 3 state is discussed in terms of mode hybridisation between the optical and acoustic modes. The FMR modes' in symmetric square ASI temperature dependence is measured, and the mode shifts are discussed. Remanence FMR measurements show how the characteristic of square ASI reversal and equivalent magnetisation microstates may be identified using spin-wave spectra.