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Topological band-order transition and quantum spin Hall edge engineering in functionalized X-Bi(111) (X?=?Ga, In, and Tl) bilayer.

ABSTRACT: Functionalized X-Bi bilayers (X?=?Ga, In, and Tl) with halogens bonded on their both sides have been recently claimed to be the giant topological insulators due to the strong band inversion strengths. Employing the first-principles electronic structure calculation, we find the topological band order transition from the order p - p - s of the X-Bi bilayers with halogens on their both sides to the new order p - s - p of the bilayers (especially for X?=?Ga and In) with halogen on one side and hydrogen on the other side, where the asymmetric hydrogen bonding simulates the substrate. We further find that the p - s bulk band gap of the bilayer bearing the new order p - s - p sensitively depends on the electric field, which enables a meaningful engineering of the quantum spin Hall edge state by controlling the external electric field.

SUBMITTER: Kim Y

PROVIDER: S-EPMC5022058 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

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Topological band-order transition and quantum spin Hall edge engineering in functionalized X-Bi(111) (X = Ga, In, and Tl) bilayer.

Kim Youngjae Y Yun Won Seok WS Lee J D JD

Scientific reports 20160914

Functionalized X-Bi bilayers (X = Ga, In, and Tl) with halogens bonded on their both sides have been recently claimed to be the giant topological insulators due to the strong band inversion strengths. Employing the first-principles electronic structure calculation, we find the topological band order transition from the order p - p - s of the X-Bi bilayers with halogens on their both sides to the new order p - s - p of the bilayers (especially for X = Ga and In) with halogen on one side and hydro ...[more]

PMID: 27623710

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