Quantum Anomalous Hall Insulator in Asymmetrically Functionalized Germanene
ORAL
Abstract
We study the atomic structures and electronic properties of honeycomb germanene passivated asymmetrically with hydrogen and nitrogen (GeHN) atoms using first-principles electronic structure calculations. There are three atomic structures considered: planar, buckled, and inversely buckled honeycomb. We found that the inversely buckled structure is in non-magnetic insulator phase; while the buckled structure is metallic. Using spin-polarized calculations with spin-orbit coupling, GeHN in planar structure was identified to exhibit a quantum anomalous Hall (QAH) insulator phase. In order to confirm the topology of the material, we further calculated the Chern number as well as the edge states. A band connecting the conduction and the valence band was found at the edge state of zigzag GeHN nanoribbon. Our results suggest that functionalized germanene might be used in the highly sought spintronic applications based on QAH effect.
–