Surface States and Angle-Resolved Photoemission Spectra from ${\mathrm{Nd}}_{2-\mathit{x}}{\mathrm{Ce}}_{\mathit{x}}{\mathrm{CuO}}_4$ Superconductor

By carrying out first-principles angle-resolved photoemission (ARPES) computations within the local-density-approximation-based band theory framework, we predict the existence of surface states on the (001) surface of the superconductor ${\mathrm{Nd}}_{2-x}{\mathrm{Ce}}_x{\mathrm{CuO}}_4$ (NCCO). Two surface state bands are identified in the vicinity of the Fermi energy. The associated states possess quite different characteristics in terms of their binding energy, dispersion with $k_{\parallel }$, and the polarization and photon energy dependence. Our theoretical predictions offer new insight into the existing ARPES data on NCCO with which they are consistent.