Stacking-dependent electronic structure of ultrathin perovskite bilayers

• Main Authors: Larson, Daniel T, Bennett, Daniel, Ali, Abduhla, Chaves, Anderson S, Arora, Raagya, Rabe, Karin M, Kaxiras, Efthimios
• Format: Journal Article
• Language: English
• Published: 25-11-2024
• Subjects: Physics - Materials Science; Physics - Mesoscale and Nanoscale Physics
• DOI: 10.48550/arxiv.2411.16497

Twistronics has received much attention as a new method to manipulate the
properties of 2D van der Waals structures by introducing moir\'e patterns
through a relative rotation between two layers. Here we begin a theoretical
exploration of twistronics beyond the realm of van der Waals materials by
developing a first-principles description of the electronic structure and
interlayer interactions of ultrathin perovskite bilayers. We construct both an
ab initio tight-binding model as well as a minimal 3-band effective model for
the valence bands of monolayers and bilayers of oxides derived from the
Ruddlesden-Popper phase of perovskites, which is amenable to thin-layer
formation. We illustrate the approach with the specific example of
Sr$_2$TiO$_4$ layers but also provide model parameters for Ca$_2$TiO$_4$ and
Ba$_2$TiO$_4$ .