Epitaxial Stabilization of a Pyrochlore Interface between Weyl Semimetal and Spin Ice.

Pyrochlore materials are known for their exotic magnetic and topological phases arising from complex interactions among electron correlations, band topology, and geometric frustration. Interfaces between different pyrochlore crystals characterized by complex many-body ground states hold immense potential for novel interfacial phenomena due to the strong interactions between these phases. However, the realization of such interfaces has been severely hindered by limitations in material synthesis methods. In this study, we discover a robust synthesis method that produces the previously unexplored epitaxial pyrochlore interface between spin ice Dy ₂ Ti ₂ O ₇ and Weyl semimetal Eu ₂ Ir ₂ O ₇ . The method relies on an ultrahigh supersaturation regime during deposition aided by directional IR-laser-driven thermal gradients, transforming amorphous covalent networks into nearly perfectly ordered, atomically sharp interfaces with a chemically ideal arrangement of ions. The novel pyrochlore interface enables the study of interactions between relativistic Weyl fermions and spin ice magnetic monopoles, opening a path to designing diverse pyrochlore interfaces.