Flat band induced by non-collinear antiferromagnetism in two-dimensional CoBi2Te4

Ziyuan Zhao

Ziyuan Zhao, Monash

The interplay of the topology of electronic wavefunctions with spin configurations in intrinsically magnetic topological insulators (TIs) causes various exotic topological states, which attracts much attention in condensed matter physics. In this work, we study the magnetic and electronic properties and edge states of two-dimensional CoBi2Te4.

Based on our density functional theory and tight-binding calculations, CoBi2Te4 films are predicted to present intrinsic intralayer non-collinear antiferromagnetism (ncAFM). Interestingly, a flat band is obtained in the edge state of (210) nanoribbon. The appearance of the flat band is attributed to the magnetic inhomogeneities caused by the intralayer ncAFM coupling, because it is still preserved in the (210) nanoribbon of CoBi2Te4-Bi2Te3 heterostructure.

About the presenter

Ziyuan Zhao is a PhD Student with CI Nikhil Medhekar undertaking research linked with FLEET’s Research Theme 1, Topological Materials.