CuTe chains on Cu(111) by deposition of one-third of a monolayer of Te: Atomic and electronic structure
Tilman Kißlinger, Andreas Raabgrund, B. Geldiyev, Maximilian Ammon, Janek Rieger, Jonas Hauner, Lutz Hammer, Thomas Fauster, M. Alexander Schneider
Abstract
The surface atomic and electronic structure after deposition of one-third of a monolayer Te on Cu(111) was determined using a combination of low-energy electron diffraction (LEED), scanning tunneling microscopy and spectroscopy (STM/STS), angle-resolved single and two-photon photoelectron spectroscopy (ARPES /AR-2PPE), and density functional theory (DFT) calculations. Contrary to the current state in literature, Te does not create a two-dimensional surface alloy but forms ${\mathrm{Cu}}_{2}{\mathrm{Te}}_{2}$ adsorbate chains in a $\left(2\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}\right){\text{R30}}^{\ensuremath{\circ}}$ superstructure. We establish this by a high-precision LEED-IV structural analysis with Pendry $R$ factor of $R=0.099$ and corroborating DFT and STM results. The electronic structure of the surface phase is dominated by an anisotropic downward dispersing state at the Fermi energy ${E}_{F}$ and a more isotropic upward dispersing unoccupied state at $E\ensuremath{-}{E}_{F}=+1.43\phantom{\rule{0.16em}{0ex}}\text{eV}$. Both states coexist with bulk states of the projected band structure, and are therefore surface resonances.