Massless Dirac Fermions in ZrTe Semimetal Grown on InAs(111) by van der Waals Epitaxy.

Single and few layers of the two-dimensional (2D) semimetal ZrTe are grown by molecular beam epitaxy on InAs(111)/Si(111) substrates. Excellent rotational commensurability, van der Waals gap at the interface and moiré pattern are observed indicating good registry between the ZrTe epilayer and the substrate through weak van der Waals forces. The electronic band structure imaged by angle resolved photoelectron spectroscopy shows that valence and conduction bands cross at the Fermi level exhibiting abrupt linear dispersions. The latter indicates massless Dirac Fermions which are maintained down to the 2D limit suggesting that single-layer ZrTe could be considered as the electronic analogue of graphene.