Metal-insulator phase transition and topology in a three-component system

TL;DR

This study explores a three-component dice lattice model revealing tunable metal-insulator transitions and diverse topological phases, including high Hall plateau states, through band structure analysis and Chern number calculations.

Contribution

It introduces a detailed analysis of topological phases and metal-insulator transitions in a three-component lattice with complex hopping and sublattice potentials, expanding understanding of topological materials.

Findings

Metal-insulator transition modulated by Fermi energy and parameters

Discovery of rich topological phases with high Hall plateaus

Confirmation of bulk-edge correspondence via edge-state spectra

Abstract

In the framework of the tight binding approximation, we study a non-interacting model on the three-component dice lattice with real nearest-neighbor and complex next-nearest-neighbor hopping subjected to $\Lambda$- or V-type sublattice potentials. By analyzing the dispersions of corresponding energy bands, we find that the system undergoes a metal-insulator transition which can be modulated not only by the Fermi energy but also the tunable extra parameters. Furthermore, rich topological phases, including the ones with high Hall plateau, are uncovered by calculating the associated band's Chern number. Besides, we also analyze the edge-state spectra and discuss the correspondence between Chern numbers and the edge states by the principle of bulk-edge correspondence.