Electronic Structure of Bi Honeycomb on Si(111)-α-√3×√3-Au
Hsin-Lei Chou1*, Chia-Hsiu Hsu1, Shih-Yu Wu1, Hsin Lin2, Feng-Chuan Chuang1, Chien-Cheng Kuo1
1Department of Physics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
2Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117542, Singapore
* presenting author:Hsin-Lei Chou, email:s861982002@gmail.com
The Bismuth (Bi) with the honeycomb structure on Si(111)-α-√3×√3-Au is one of candidates to realize the two dimensional topological insulator [1-2]. In our previous study, the presence of Bi honeycomb was already confirmed by scanning tunneling microscopy (STM) and the relative band structure was also proposed by the theoretical calculation [1-3]. However, the direct experimental evidence to prove whether Bi honeycomb shows topological properties remained lacking so far. Here, we addressed this issue by detailed measurements of its electronic properties using scanning tunneling spectroscopy. Bi deposited on Si(111)-α-√3×√3-Au forms the 2D islands with honeycomb structure. The honeycombed Bi islands displays the higher conductivity at their edges than that on the surfaces far from the edges, which implies the presence of the edge state. Furthermore, their quasiparticle interference patterns were mapped to show the q-space band dispersion. Detailed comparison and discussion were also made in this work.

[1] Feng-Chuan Chuang, Chia-Hsiu Hsu, Hsin-Lei Chou, Christian P. Crisostomo, Zhi-Quan Huang, Shih-Yu Wu, Chien-Cheng Kuo, Wang-Chi V. Yeh, Hsin Lin and Arun Bansil. Phys. Rev. B, 93, 035429 (2016).
[2] Bing Huang, Kyung-Hwan Jin, Houlong L. Zhuang, Lizhi Zhang and Feng Liu. Phys. Rev. B, 93, 035429 (2016).
[3] Hsin-Lei Chou, Chia-Hsiu Hsu1, Shih-Yu Wu, Hsin Lin, Feng-Chuan Chuang and Chien-Cheng Kuo (Unpublised).

Keywords: Topological insulator, Si(111)-α-√3×√3-Au, Bismuth, Scanning tunneling microscopy, Quasiparticle interference