Topological edge states induced by the Zak phase in A 3 B monolayers

カテゴリ:Publications 

2019年2月20日

Topological edge states induced by the Zak phase in A3Bmonolayers,
Tomoaki Kameda, Feng Liu, Sudipta Dutta, and Katsunori Wakabayashi
Phys. Rev. B 99, 075426 (2019).

Published 19 February 2019

Abstract:

In crystalline systems, charge polarization is related to the Zak phase determined by bulk band topology. Nontrivial charge polarization induces robust edge states accompanied by fractional charge. In the Su-Schrieffer-Heeger model, it is known that the strong modulation of electron hopping causes nontrivial charge polarization even in the presence of inversion symmetry. Here, we consider a biatomic honeycomb lattice to introduce such strong modulation, i.e., a A3B sheet. By tuning the hopping ratio and on-site potential difference between the A and B atoms, we show that the topological phase transition characterized by the Zak phase occurs. Furthermore, we propose that C3N and BC3 are possible realistic materials on the basis of first-principles calculations. Both of them display topological edge states induced by the Zak phase without spin-orbital couplings and external fields, unlike conventional topological insulators.

Received 3 October 2018
DOI:https://doi.org/10.1103/PhysRevB.99.075426

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