Magnetism in iridate heterostructures leveraged by structural distortions

Heterostructuring of complex oxides into superlattices is an emerging method that provides new avenues to stabilize ground states unavailable to bulk synthesis. Artificial analogues to the Ruddlesen-Popper series iridates, composed of metallic SrIrO₃ interspaced with band insulating SrTiO₃, are shown to conserve the bulk-like spin-flop transition through resonant elastic scattering. However, measurements of the magnetic excitation spectrum with resonant inelastic scattering evidence a strong alteration in the stability of the magnetic ground state, driven by structural distortions not present in the bulk materials. These results point to heterostructuring as a powerful method for modulating the magnetic ground state of complex oxides hosting strong spin-orbit coupling.