Fig. 1: Lattice and spin structure of pyrochlore spin ice, antiferromagnet, and their interface.
From: Two-dimensional magnetic monopole gas in an oxide heterostructure
a, b Illustrations of lattice and spin structures of a spin ice pyrochlore R2Ti2O7 and an antiferromagnetic pyrochlore R2Ir2O7 respectively, where the nearest neighbor interaction between R3+ moments Jeff and the d–f interaction between a R3+ moment and an Ir4+ moment Jdf are shown. The arrows represent the local moments. The tetrahedral sites with magnetic charge Q = 0 are in gray, Q = qm in green, Q = −qm in yellow, Q = 2qm in blue, and Q = −2qm in red. c Illustration of lattice and spin structure of an R2Ir2O7/R2Ti2O7 interface with Jdf >  2 Jeff, where the spin ice layer are forced to adopt a fully polarized state. The complete/truncated Ir4+ hexagons are highlighted in green and the complete/reduced local exchange fields experienced by the R3+ moments are materialized by green arrows.
