Emergent phenomena at interfaces of KTaO₃

With an ever intensifying hunt for quantum materials with integrated functionalities, transition metal oxides provide a simple yet rich option to explore. In this article, we bring out the potential of a perovskite oxide KTaO₃ (KTO)as a candidate for future generation quantum technologies as well as a hunting ground to understand the topological effects in oxides. We show that the heterostructures of insulating KTO with other insulating oxides LaVO₃ (LVO) and EuO are not only conducting, but have strong spin-orbit coupling leading to momentum-dependent spin-splitting—the Rashba effect. In LVO–KTO, the Rashba spin-split bands are shown to give rise to anisotropic magnetoresistance and planar Hall effect, while in EuO–KTO, a non-trivial Berry's phase analysed from the quantum Shubnikov-de Haas oscillations is observed. (author)