Quantum Anomalous Hall Effect and Tunable Topological States in 3d Transition Metals Doped Silicene

Xiao-Long Zhang,Wu-Ming Liu,Lan-Feng Liu

doi:10.1038/srep02908

Abstract

Silicene is an intriguing 2D topological material which is closely analogous to graphene but with stronger spin orbit coupling effect and natural compatibility with current silicon-based electronics industry. Here we demonstrate that silicene decorated with certain 3d transition metals (Vanadium) can sustain a stable quantum anomalous Hall effect using both analytical model and first-principles Wannier interpolation. We also predict the quantum valley Hall effect and electrically tunable topological states could be realized in certain transition metal doped silicene where the energy band inversion occurs. Our findings provide new scheme for the realization of quantum anomalous Hall effect and platform for electrically controllable topological states which are highly desirable for future nanoelectronics and spintronics application.

Highlights

Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
Our findings provide new scheme for the realization of quantum anomalous Hall effect and platform for electrically controllable topological states which are highly desirable for future nanoelectronics and spintronics application
From combined tight-binging (TB) model analysis and firstprinciples Wannier interpolation, we show that the Vanadium doped silicene hosts a stable quantum anomalous Hall effect (QAHE) which survives strong correlation effect of the adatom, and this system can be half-metallic[31] if the Fermi level is properly tuned

Summary

Introduction

A striking difference between silicene and graphene is that the stable silicene monolayer has additional buckling degree[20], which accounts for the relatively large (1.55 meV) spin orbit coupling (SOC) induced gap[25] in silicene and a couple of unusual quantum phenomena recently reported[26,28,29,30]. These features together with the natural compatibility with current silicon-based microelectronics industry make silicene a promising candidate for future nanoelectronics application. We predict the resulting QAHE and QVHE can be tuned directly using an external electrical field, which is rather appealing for future nanoelectronics and spintronics application

Methods

Results

Conclusion