“Artificial spin ice” is a term used for arrays of nanoscale magnetic islands on lattices that geometrically frustrate inter-island interactions. Such systems are tunable and provide a platform for the study of frustration, a concept of broad importance. In recent work, postdoc Liam O’Brien, and IRG-3 member Chris Leighton, in collaboration with Prof. Peter Schiffer of the Univ. of Illinois, and other groups at Penn State and Los Alamos, have demonstrated a means to anneal artificial spin ice into a thermalized state. This provides the first glimpse of the true ground state of these arrays, leading to the discovery of small crystallites exhibiting magnetic charge ordering, a theoretically predicted phenomenon that could not previously be accessed.
