Comment on "Creating in-plane pseudomagnetic fields in excess of 1000 T by misoriented stacking in a graphene bilayer"

TL;DR

This paper critiques a previous claim that twisted bilayer graphene's electronic properties can be mimicked by an in-plane magnetic field, showing that their spectral symmetries and low-energy behaviors differ significantly when analyzed properly.

Contribution

The authors demonstrate that considering the supercell Brillouin zone reveals fundamental differences in spectra, invalidating the analogy with in-plane magnetic fields.

Findings

Spectral symmetries differ between twisted bilayer graphene and in-plane magnetic field scenarios.

Low-energy spectra are fundamentally different when analyzed in the supercell Brillouin zone.

The previous mapping neglects superperiodic effects, leading to incorrect conclusions.

Abstract

In a recent paper [Phys. Rev. B 89, 125418 (2014)], the authors argue that it is possible to map the electronic properties of twisted bilayer graphene to those of bilayer graphene in an in-plane magnetic field. However, their description of the low-energy dynamics of twisted bilayer graphene is restricted to the extended zone scheme and therefore neglects the effects of the superperiodic structure. If the energy spectrum is studied in the supercell Brillouin zone, we find that the comparison with an in-plane magnetic field fails because (i) the energy spectra of the two situations exhibit different symmetries and (ii) the low-energy spectra are very different.