Figure 1: The dipolar dice lattice.

(a) Schematic of a two-dimensional dipolar dice lattice with elongated nanomagnets. Being a system with mixed coordination numbers, the lattice exhibits z6 vertices, where six nanomagnets meet, and z3 vertices where three nanomagnets meet. While the background lattice is defined by a lattice constant a=500 nm, the dipolar coupling between the nanomagnets is varied by changing the lattice spacing (2r=500, 545 and 600 nm). (b) Vertex types (at z6 vertices) listed with increasing energy from V1 to V8 together with their respective degeneracies g and their net emergent magnetic charges Q_z6. In a low-energy configuration, z3-vertices obey the ice rule (two-in-one-out or vice versa) with a net magnetic charge Q_z3=±q. (c) X-ray magnetic circular dichroism (XMCD) images of thermally activated dipolar dice lattice. Nanomagnets with moments pointing towards the incoming X-rays (indicated by red arrow) appear dark, while moments opposing the incoming X-rays appear bright. An emergent magnetic charge defect at a z6 vertex site with an overall charge Q_z6=±2q (cyan blue circle) is initially unscreened, as it is surrounded by three +q and three −q charges at the z3 vertices (at t=0 s). Eventually, a +q at a z3 vertex is transformed into a −q charge, which results in a screened state (at t=7 s) with an overall charge of . The screened charge defect decays at t=28 s. The yellow scale bar indicates a length of 545 nm.