Topological line defects in bilayer graphene

Speaker: Dr. Bor-Luen Huang (NCKU)

Date/Time: 2018.07.19/11:20

Abstract:

Few-layer graphene has various geometric structures, which can be manipulated by stacking configuration and external field, and huge potential for fundamental physics and applications. Recently, bilayer graphene have attracted a lot of attention because of the discovery of superconductivity in twisted bilayer graphene. On the other side, extensive interests focus on the topological materials, which have gapless topological protected states around boundaries and geometry defects. Crystalline topological line defects, which are domain walls discussed in the manuscript, can be generated by different Bernal stacking and mapped out locally in twisted bilayer graphene. Therefore, a detailed study of geometric effect in bilayer graphene could provide us valuable insights to understand those peculiar physical phenomena. In this talk, we show the effects caused by geometry modulation and gate voltage in bilayer graphene. We present energy subbands, tight-binding functions, density of states, and optical absorption spectra. The observations are connectable to experimental measurements of electronic and optical properties of bilayer graphene.

[1] Bor-Luen Huang, Chih-Piao Chuu, and Ming-Fa Lin, arXiv: 1805.10775.