Magnetic-Field Control of Emergent Order in a 3D Dipolar Pyramid Artificial Spin Ice

Abstract: We realize a three-dimensional artificial spin ice of disconnected nanomagnets interacting solely via dipolar coupling, patterned on square pyramids. This Pyramid artificial spin ice, with both tilted and in-plane nanomagnets, supports tunable states. Monte Carlo simulations reveal a rich phase diagram and an emergent square ice of vertex-level effective spins. Tailored demagnetization protocols and magnetic force microscopy allow experimental access to low-energy states, establishing a platform for exploring three-dimensional artificial spin ices.