Observation of the one-dimensional band structure of thallium chains adsorbed on copper (100)

The electron energy-wavevector (E-k) dispersion relation for linear chains of thallium atoms adsorbed on the copper (100) surface has been determined with angle-resolved photoelectron spectroscopy. The behaviour of the Tl 6s and Tl 6p emission features is consistent with a simple one-dimensional band structure. For k parallel to the chains the 6s dispersion curve is sinusoidal and in good agreement with the result of an LCAO calculation using relativistic Hartree-Fock-Slater wavefunctions. Electrons emitted from the Cu 3d surface resonance are coherently scattered for wavevectors parallel to the chains.