Tunable metal–insulator transition in LaTiO3/CaVO3 superlattices: A theoretical study* *Project supported by the National Natural Science Foundation of China (Grant Nos. 11804168 and 51872145), the Natural Science Foundation of Jiangsu Province, China (Grant Nos. BK20180736 and BK20190726), the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 18KJB140009), and the Science Foundation from Nanjing University of

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.