Angle-dependent physical properties of 2D van der Waals heterostructures
Until now, much has been done to study, theoretically and experimentally, the physical properties of two vertically stacked G layers with a different crystallographic orientation between them characterized by an angle. This angle between layers emerges as a new degree of freedom, which specifies physical properties such as electronic, optical, chemical, among others. Some exciting experimental results have been found very recently in these superlattices, but deep theoretical understanding has been lagged. One of the reasons is that typical electronic structure analysis methods are insufficient. In particular, band structures get crowded because of Brillouin Zone folding, making their interpretation cumbersome. In this talk, we present a methodology that allows us to elucidate the physical effects of the mutual interactions between 2D layers by unfolding the electronic bands of systems with double periodicity. This method reveals that new gaps that turn into discrete-like states evenly-spaced in energy arise and are modulated when the interlayer angle decreases. These electronic states might be relevant to explain, for instance, electron-phonon assisted effects recently observed in experiments.