Figure 1

Topography images of ASI systems as well as schematics defining magnetic charges at border and central vertices. AFM images of square ASI vertices with closed edges resembling a stained glass window (a) and a deformed stained glass window (b). The stadium shaped nanomagnets are of dimensions \(300 \times 100 \times 25\) nm\(^3\) and are magnetically in single domain state. In the deformed stained glass window, the misaligned nanomagnet is placed at 30\(^{\circ }\) with respect to the long axis of the vertical nanomagnets. The applied magnetic field direction is at an angle of \(10^{\circ }\) and \(7^{\circ }\) with respect to the vertical nanomagnets for the window patterns (a,b), respectively. (c) shows the possible vertex configurations for \(z=4\) vertex with nomenclatures of different types (type-I, type-II,...etc.) of spin ice vertices. Schematics of possible orientations of magnetization, magnetic charges in the nanomagnets under dumbbell model and net charges at edge vertices for \(z=3\) (d) and corners (e).