Chin. Phys. B, 2021, Vol. 30(1): 010302    DOI: 10.1088/1674-1056/abb305
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# Metal-insulator phase transition and topology in a three-component system

Shujie Cheng(成书杰) and Xianlong Gao(高先龙)†
Department of Physics, Zhejiang Normal University, Jinhua 321004, China
Abstract  Due to the topology, insulators become non-trivial, particularly those with large Chern numbers which support multiple edge channels, catching our attention. In the framework of the tight binding approximation, we study a non-interacting Chern insulator 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. In general, our results suggest that there are large Chern number phases with C= 3 and the work enriches the research about large Chern numbers in multiband systems.
Keywords:  band structures      high Chern numbers      bulk-edge correspondence
Received:  18 June 2020      Revised:  08 August 2020      Accepted manuscript online:  27 August 2020
 PACS: 03.65.Vf (Phases: geometric; dynamic or topological) 05.30.Rt (Quantum phase transitions)
Fund: Project supported by the National Natural Science Foundation of China (Grant Nos. 11835011 and 11774316).
Corresponding Authors:  Corresponding author. E-mail: gaoxl@zjnu.edu.cn