Observation of Dirac-like band dispersion in LaAgSb2

Abstract

We present a combined angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations study of the electronic structure of LaAgSb2 in the entire first Brillouin zone. We observe a Dirac-cone-like structure in the vicinity of the Fermi level formed by the crossing of two linear energy bands, as well as the nested segments of a Fermi surface pocket emerging from the cone. Our ARPES results show the close relationship of the Dirac cone to the charge-density-wave ordering, providing consistent explanations for exotic behaviors in this material.