Edge states of hydrogen terminated monolayer materials: silicene, germanene and stanene ribbons. (7th February 2017)

• Record Type: Journal Article
• Authors: Hattori, Ayami; Tanaya, Sho; Yada, Keiji; Araidai, Masaaki; Sato, Masatoshi; Hatsugai, Yasuhiro; Shiraishi, Kenji; Tanaka, Yukio
• Is Part Of: Journal of physics. Volume 29:Number 11(2017)
• Publication Date: 2017-02-07
• Subjects: edge states -- multi-orbital model -- non-linear dispersion -- low-buckled structure; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aa57e0
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We investigate the energy dispersion of the edge states in zigzag silicene, germanene and stanene nanoribbons with and without hydrogen termination based on a multi-orbital tight-binding model. Since the low buckled structures are crucial for these materials, both the π and σ orbitals have a strong influence on the edge states, different from the case for graphene nanoribbons. The obtained dispersion of helical edge states is nonlinear, similar to that obtained by first-principles calculations. On the other hand, the dispersion derived from the single-orbital tight-binding model is always linear. Therefore, we find that the non-linearity comes from the multi-orbital effects, and accurate results cannot be obtained by the single-orbital model but can be obtained by the multi-orbital tight-binding model. We show that the multi-orbital model is essential for correctly understanding the dispersion of the edge states in tetragen nanoribbons with a low buckled geometry.