Emergence of Flat Bands in Type-II Weyl Semimetal

We study candidate type-II Weyl semimetals using density functional theory (DFT) and angle-resolved photoemission spectroscopy (ARPES). We identify two distinct terminations in each due to the noncentrosymmetric crystal structure. The DFT calculations show ten sets of Weyl points in one compound and four sets of Weyl points in another. Experimental data reveals flat bands throughout a large portion of the Brillouin zone in one of the compounds, which are not predicted in the calculations. The unusual band structure of these materials provides a unique opportunity to study the interplay of nontrivial topology and strongly interacting electrons in a noncentrosymmetric system.