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arXiv · 1707.03116

Periodicity-free unfolding method of electronic energy spectra: Application to twisted bilayer graphene

Taichi Kosugi·Hirofumi Nishi·Yasuyuki Kato·Yu-ichiro Matsushita
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Abstract

We propose a novel periodicity-free unfolding method of the electronic energy spectra. Our new method solves a serious problem that calculated electronic band structure strongly depends on the choice of the simulation cell, i.e., primitive-cell or supercell. The present method projects the electronic states onto the free-electron states, giving rise to the {\it plane-wave unfolded} spectra. Using the method, the energy spectra can be calculated as a completely independent quantity from the choice of the simulation cell. We have examined the unfolded energy spectra in detail for three models and clarified the validity of our method: One-dimensional interacting two chain model, monolayer graphene, and twisted bilayer graphene. Furthermore, we have discussed that our present method is directly related to the experimental ARPES (Angle-Resolved Photo-Emission Spectroscopy) spectra.

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Taichi Kosugi, Hirofumi Nishi, Yasuyuki Kato, Yu-ichiro Matsushita. 2017-07-11. Periodicity-free unfolding method of electronic energy spectra: Application to twisted bilayer graphene. https://arxiv.org/abs/1707.03116

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