Electrically tunable multiple Dirac cones in thin films of the (LaO)2(SbSe2)2 family of materials

• Published in: Nature communications Vol. 6; no. 1; p. 8517
• Main Authors: Dong, Xiao-Yu, Wang, Jian-Feng, Zhang, Rui-Xing, Duan, Wen-Hui, Zhu, Bang-Fen, Sofo, Jorge O., Liu, Chao-Xing
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.10.2015; Nature Publishing Group
• Subjects: 639/766/119/544; 639/766/419/1133; Anisotropy; Condensed matter physics; Cones; Electric fields; Electronic devices; Electronic equipment; First principles; Graphene; Humanities and Social Sciences; multidisciplinary; Physics; Quantum Hall effect; Science; Science (multidisciplinary); Spin-orbit interactions; Stability; Thin films; Topological insulators
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms9517

Two-dimensional Dirac physics has aroused great interests in condensed matter physics ever since the discovery of graphene and topological insulators. The ability to control the properties of Dirac cones, such as bandgap and Fermi velocity, is essential for various new phenomena and the next-generation electronic devices. On the basis of first-principles calculations and an analytical effective model, we propose a new Dirac system with eight Dirac cones in thin films of the (LaO) 2 (SbSe 2 ) 2 family of materials, which has the advantage in its tunability: the existence of gapless Dirac cones, their positions, Fermi velocities and anisotropy all can be controlled by an experimentally feasible electric field. We identify layer-dependent spin texture induced by spin–orbit coupling as the underlying physical reason for electrical tunability of this system. Furthermore, the electrically tunable quantum anomalous Hall effect with a high Chern number can be realized by introducing magnetization into this system. The ability to electrically control Dirac cones is essential for exploring the physics and applications of Dirac materials. Here, the authors combine ab initio calculations and analytical models to predict that (LaO) 2 (SbSe 2 ) 2 is a Dirac material with multiple electrically-tunable Dirac cones.