Quantum mechanical studies of helium atom scattering from isolated CO molecules on metal surfaces

摘要

We review two distinct quantum mechanical theories of atomic scattering from a point defect, single adsorbate or vacancy, inducing a corrugation much larger than that of the crystal surface. They are both based upon unrestricted motion of the probe and involve a realistic interaction potential. The most sophisticated one is a pseudospectral wavepacket method that is presented in both Cartesian and cylindrical representations. The physically attractive, albeit more approximate, close-coupling gas phase approach is also considered. We report the first realistic comparison with the experimental measurements of helium atom scattering on CO/Cu(100), at a beam energy of 20 meV. The combined use of the gas phase and of the reference models enables the unambiguous interpretation of all experimental peaks. [References: 55]