Abstract
Using density functional theory calculations, we establish that the half-metallicity of bulk survives down to 1 nm thickness in heterostructures grown along the (001) and (111) directions. The confinement of the two-dimensional (2D) electron gas in this quantum well structure arises from the suppressed hybridization between Re/Fe states and unoccupied Ti states, and it is further strengthened by polar fields for the (111) direction. This mechanism, distinct from the polar catastrophe, leads to an order of magnitude stronger confinement of the 2D electron gas than that at the interface. We further show low-energy bands of (111) heterostructure display nontrivial topological character. Our work opens up the possibility of realizing ultrathin spintronic devices.
- Received 28 July 2015
- Revised 27 September 2015
DOI:https://doi.org/10.1103/PhysRevB.92.161106
©2015 American Physical Society