Intrinsic three-dimensional topology in SrNbO₃ films

Transition metal oxides, with their wide range of electronic and magnetic properties, offer a remarkable platform for developing future electronics based on unconventional quantum phenomena, such as topological phases. The formation of topologically nontrivial states is linked to crystalline symmetry, spin-orbit coupling, and magnetic ordering. Here, by employing angle-resolved photoemission spectroscopy (ARPES), supported by density functional theory (DFT) calculations, we demonstrated that intrinsic octahedral rotations in SrNbO₃ films drive the emergence of non-trivial band topology. Specifically, ARPES reveals and diffraction data confirm the presence of in-phase a⁰a⁰c⁺ octahedral rotation, leading to the formation of topologically protected Dirac band crossings, giving rise to massless fermions in this system. Our study underscores the pivotal role of structural distortions in transition metal oxides, illustrating how they can be strategically harnessed to unlock and stabilize quantum topological states. This approach contributes to the broader understanding of quantum materials and their promising applications in advanced technologies.