Tunable Geometrical Frustration in Nanomagnet Arrays

Two-dimensional nanomagnet arrays known as "artificial spin ice" have become a valuable model system with which to explore on the microscopic scale the behavior of frustrated spin systems with competing interactions. The magnetic moments of the individual nanoislands can be resolved by magnetic force microscopy and other techniques, and the array lattice constant and even geometry can be tuned far more easily than in natural materials. This talk will describe how artificial spin ice has reproduced some of the key features of natural frustrated materials, including magnetic monopole excitations and ground state degeneracy. The recent development of effective thermalization processes, time-resolved imaging of thermal fluctuations, and the possibility of three-dimensional artificial spin ice all point to the continued utility of these systems in elucidating interesting physical phenomena in magnetic materials.