Electronic properties and lattice dynamics of the As(111) surface

The bulk and surface electronic and structural properties of As(111) have been studied with first-principles methods. The inclusion of spin-orbit interaction reveals that As shares the same topologically nontrivial order of the bulk electronic bands of Sb which gives rise to two spin-polarized surface states connecting valence-like and conduction-like states. Bulk and surface phonons have been calculated by means of density functional perturbation theory. The surface phonon bands reveal features related to a remarkable stiffening of the surface bilayer with respect to the bulk ones similarly to what is measured for the Bi(111) and to what is expected for the Sb(111) surface.