Uncovering the interplay of magnetic sublattices in rare-earth pyrochlore Ho₂Ir₂O₇

Rare-earth pyrochlore iridates R₂Ir₂O₇ (e.g., R = rare-earth elements) are an exciting class of quantum materials that exhibit emergent electronic and magnetic phenomena. A little-explored member of the family, Ho₂Ir₂O₇, has been reported to host a spin-ice configuration on the Ho sites while maintaining all-in-all-out order on the Ir sites; however, the presence of two distinct magnetic sublattices on Ho³⁺ (4f-electrons) and Ir⁴⁺ (5d-electrons) has opened intriguing questions about the 4f-5d interaction which may result in unusual electronic and magnetic properties. In this talk, I will present our recent results on the first successful resonant X-ray spectroscopy experiments on (111)-oriented Ho₂Ir₂O₇ thin films. These results reveal the unexpected effect of the Ho sublattice on the magnetic and orbital ground states of this pyrochlore compound.