Tunable metal–insulator transition in LaTiO3/CaVO3 superlattices: A theoretical study*

Abstract

As one of intriguing physical results of electronic reconstruction, the metal–insulator transition plays an important role in exploring new electronic devices. In this study, the density functional theory is employed to investigate the metal–insulator transition in (LaTiO3) m /(CaVO3) n superlattices. Herein, three kinds of physical avenues, i.e., stacking orientation, epitaxial strain, and thickness periods, are used to tune the metal–insulator transition. Our calculations find that the [001]- and [110]-oriented (LaTiO3)1/(CaVO3)1 superlattices on SrTiO3 substrate are insulating, while [111]-oriented case is metallic. Such metallic behavior in [111] orientation can also be modulated by epitaxial strain. Besides the structural orientation and strain effect, the highly probable metal–insulator transition is presented in (LaTiO3) m /(CaVO3) n superlattices with increasing thickness. In addition, several interesting physical phenomena have also been revealed, such as selective charge transfer, charge ordering, and orbital ordering.