Electronic Structure of Superlattices in Graphene
Szu-Chao Chen1*, Wun-Hao Kang1, Ming-Hao Liu1
1Department of Physics, National Cheng Kung University, Tainan, Taiwan
* Presenter:Szu-Chao Chen, email:szuchaochen@gmail.com
We calculate miniband structures of superlattices in single-layer graphene, including graphene/hBN moire and gate-defined superlattices within the continuum model and compare them with our quantum transport simulations based on the scalable tight-binding model [1]. Good agreement between miniband structures and the corresponding transport simulations confirms the reliability of our calculations. Our transport results agree well with recent transport experiments for gate-controllable square superlattices [1,2] and graphene/hBN moire superlattice [1,3]. Different from the two-dimensional graphene superlattices, the gate-controllable one-dimensional graphene superlattices give rise to velocity renormalization in the original Dirac cone and the emergence of additional zero-energy Dirac points which can be further cloned to higher energies and accessible by tuning the average carrier density [4]. Our recent progresses therefore pave the way toward miniband structure engineering using graphene superlattices of arbitrary lattices, such as honeycomb or Lieb.

[1] Szu-Chao Chen, Rainer Kraft, Romain Danneau, Klaus Richter, Ming-Hao Liu Commun. Phys. 3, 71 (2020).
[2] Robin Huber, Ming-Hao Liu, Szu-Chao Chen, Martin Drienovsky, Andreas Sandner, Kenji Watanabe, Takashi Taniguchi, Klaus Richter, Dieter Weiss, Jonathan Eroms NanoLett. XXXX, (2020) https://doi.org/10.1021/acs.nanolett.0c03021.
[3] Rainer Kraft, Ming-Hao Liu, Pranauv Balaji Selvasundaram, Szu-Chao Chen, Ralph Krupke, Klaus Richter, and Romain Danneau, Phys. Rev. Lett., in production (2020) arXiv:2006.14995.
[4] Wun-Hao Kang, Szu-Chao Chen, Ming-Hao Liu, Phys. Rev. B, accepted.

Keywords: graphene, superlattice, miniband structure, quantum transport