Tuning Weyl and Multipolar States in Epitaxial Films of Pyrochlore Iridates

The pyrochlore iridates R₂Ir₂O₇ have recently emerged as a model system for exploring the intersection of topology and magnetism in correlated oxides. Their interplay of strong spin–orbit coupling, electronic correlations, and frustration gives rise to an exceptionally rich landscape of magnetic and topological phases. Recent breakthrough in epitaxial growth and heterostructure engineering now allow this balance to be controlled through additonal knobs like dimensional confinement, strain, and interfacial coupling. In this talk I will discuss how these approaches have enabled the realization of a correlated Weyl semimetal phase in the family of (111)-oriented films, multipole orders, and chiral spin-liquid-like behavior in the quasi-two-dimensional limit. Novel interfaces between anti-ferromagnetic pyrochlore iridates and spin-ice pyrochlores result in novel anisotropic and topological quantum states. These results establish artificial structures of pyrochlore iridates as a versatile new platform to design and control topologically non-trivial magnetic states.