Doping-controlled surface conduction in topological insulators with warping effects

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:536

Article

Arabikhah, M.¹  Saffarzadeh, A.^1,2 

[1] Payame Noor Univ, Dept Phys, POB 19395-3697, Tehran, Iran

[2] Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada

关键词: Topological Insulators;    Warping effect;    Doping;    Electric conduction;    Self-consistent t-matrix approximation;   

DOI  :  10.1016/j.jmmm.2021.168135

来源: Elsevier

【 摘 要 】

Based on a self-consistent t-matrix approximation, we explore the influence of magnetic and nonmagnetic doping on the surface electronic states and conductivity of topological insulators. We show that warping parameter has a crucial impact on the density of states and dc conductivity of the doped surfaces. As the warping strength is increased, the surface density of states at high energies is suppressed and the resonant states induced by impurities in the vicinity of the Dirac point gradually disappear. It is found that nonmagnetic impurities break electron-hole symmetry at low warping strength, while the symmetry remains unchanged when the surface is magnetically doped. Our findings reveal that surface conductivity can be controlled by tuning the doping, the direction of external magnetic field and that of impurity magnetic moments. Also, the surface conductivity features in topological insulators with warped energy dispersions are not significantly affected by the presence of impurities compared to that of materials with circular energy contour.

【 授权许可】

Free