Experimental realization of the 1D random field Ising model

We have measured magnetic-field-induced avalanches in a square artificial
spin ice array of interacting nanomagnets. Starting from the ground state
ordered configuration, we imaged the individual nanomagnet moments after
each successive application of an incrementally increasing field. The
statistics of the evolution of the moment configuration show good
agreement with the canonical one-dimensional random field Ising model. We
extract information about the microscopic structure of the arrays from our
macroscopic measurements of their collective behavior, demonstrating a
process that could be applied to other systems exhibiting avalanches.