Fig. 3: Phenomenological mechanism.

a Schematics showing the boundary in the Kagome layer between the Kagome spin ice and the saturated ice state. The tetrahedra with the 2-in-2-out configuration and the 3-in-1-out (1-in-3-out) configuration are in red and green, respectively. The blue arrows denote the sites that connect the two regions with the area highlighted in light blue indicating the boundary region where the spins are less stable. A three-dimensional schematic is showed in panel b for a pair of the tetrahedra across the boundary. c MR in the region of the anomaly from 0.45 to 1 K. The solid and dashed lines were measured with B//[111] and B//[1-10], respectively. The curves are vertically shifted for clarity and comparison purposes.