Abstract
In the two-dimensional electron gas emerging at the transition metal oxide surface and interface, various exotic electronic ordering and topological phases can become experimentally more accessible with the stronger Rashba spin-orbit interaction. Here, we present a promising route to realize significant Rashba-type band splitting using a thin film heterostructure. Based on first-principles methods and analytic model analyses, a tantalate monolayer on is shown to host two-dimensional bands originating from Ta states with strong Rashba spin splittings, nearly 10% of the bandwidth, at both the band minima and saddle points. An important factor in this enhanced splitting is the significant interband coupling, which can generically arise when the inversion symmetry is maximally broken due to the strong confinement of the 2DEG on a transition metal oxide surface. Our results could be useful in realizing topological superconductivity at oxide surfaces.
- Received 22 February 2016
- Revised 14 August 2016
DOI:https://doi.org/10.1103/PhysRevB.94.115431
©2016 American Physical Society