English

A Helium-Surface Interaction Potential of Bi$_2$Te$_3$(111) from Ultrahigh-Resolution Spin-Echo Measurements

Materials Science 2018-02-20 v1 Mesoscale and Nanoscale Physics

Abstract

We have determined an atom-surface interaction potential for the He-Bi2_2Te3_3(111) system by analysing ultrahigh resolution measurements of selective adsorption resonances. The experimental measurements were obtained using 3^3He spin-echo spectrometry. Following an initial free-particle model analysis, we use elastic close-coupling calculations to obtain a three-dimensional potential. The three-dimensional potential is then further refined based on the experimental data set, giving rise to an optimised potential which fully reproduces the experimental data. Based on this analysis, the He-Bi2_2Te3_3(111) interaction potential can be described by a corrugated Morse potential with a well depth D=(6.22±0.05) meVD=(6.22\pm0.05)~\mathrm{meV}, a stiffness κ=(0.92±0.01) A˚1\kappa =(0.92\pm0.01)~\mathrm{\AA}^{-1} and a surface electronic corrugation of (9.6±0.2)(9.6\pm0.2)% of the lattice constant. The improved uncertainties of the atom-surface interaction potential should also enable the use in inelastic close-coupled calculations in order to eventually study the temperature dependence and the line width of selective adsorption resonances.

Keywords

Cite

@article{arxiv.1802.06605,
  title  = {A Helium-Surface Interaction Potential of Bi$_2$Te$_3$(111) from Ultrahigh-Resolution Spin-Echo Measurements},
  author = {Anton Tamtögl and Michael Pusterhofer and Martin Bremholm and Ellen M. J. Hedegaard and Bo B. Iversen and Philip Hofmann and John Ellis and William Allison and S. Miret-Artés and Wolfgang E. Ernst},
  journal= {arXiv preprint arXiv:1802.06605},
  year   = {2018}
}