We have investigated Bernal-stacked tetralayer graphene as a function of interlayer distance and perpendicular electric field by using density functional theory calculations. The low-energy band structure was found to be very sensitive to the interlayer distance, undergoing a metal-insulator transition. It can be attributed to the nearest-layer coupling that is more sensitive to the interlayer distance than are the next-nearest-layer couplings. Under a perpendicular electric field above a critical field, six electric-field-induced Dirac cones with mass gaps predicted in tight-binding models were confirmed, however, our density functional theory calculations demonstrate a phase transition to a quantum valley Hall insulator, contrasting to the tight-binding model prediction of an ordinary insulator.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (Project Nos. 2016R1D1A1A09917003 and 2016R1D1A1B03931144 ). K.W.L. gratefully acknowledges a Korea University research grant.
© 2018 Korean Physical Society
Copyright 2018 Elsevier B.V., All rights reserved.
- A. Tetralayer graphene
- B. Interlayer couplings
- C. Metal-insulator transition
- D. Quantum valley Hall effect
ASJC Scopus subject areas
- Materials Science(all)
- Physics and Astronomy(all)