Provoking topology by octahedral tilting in strained SrNbO$_3$

TL;DR

This paper demonstrates how lattice distortions and octahedral rotations in strained SrNbO$_3$ films induce topologically non-trivial electronic states, verified through ARPES and DFT, highlighting octahedral engineering as a tool for quantum phase control.

Contribution

It reveals the role of octahedral tilting in SrNbO$_3$ in creating topological states, combining experimental ARPES data with theoretical DFT calculations.

Findings

Octahedral rotation induces topologically protected Dirac crossings.

Strain and lattice distortions control topological phases.

Octahedral engineering enables quantum topological phase manipulation.

Abstract

Transition metal oxides with a wide variety of electronic and magnetic properties offer an extraordinary possibility to be a platform for developing future electronics based on unconventional quantum phenomena, for instance, the topology. The formation of topologically non-trivial states is related to crystalline symmetry, spin-orbit coupling, and magnetic ordering. Here, we demonstrate how lattice distortions and octahedral rotation in SrNbO$_3$ films induce the band topology. By employing angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations, we verify the presence of in-phase $a^0a^0c^+$ octahedral rotation in ultra-thin SrNbO$_3$ films, which causes the formation of topologically-protected Dirac band crossings. Our study illustrates that octahedral engineering can be effectively exploited for implanting and controlling quantum topological phases in transition metal oxides.