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arXiv · 1802.06605

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

Anton Tamtögl·Michael Pusterhofer·Martin Bremholm·Ellen M. J. Hedegaard·Bo B. Iversen·Philip Hofmann·John Ellis·William Allison·S. Miret-Artés·Wolfgang E. Ernst
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Abstract

We have determined an atom-surface interaction potential for the He$-$Bi$_2$Te$_3$(111) system by analysing ultrahigh resolution measurements of selective adsorption resonances. The experimental measurements were obtained using $^3$He 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$-$Bi$_2$Te$_3$(111) interaction potential can be described by a corrugated Morse potential with a well depth $D=(6.22\pm0.05)~\mathrm{meV}$, a stiffness $κ=(0.92\pm0.01)~\mathrmÅ^{-1}$ and a surface electronic corrugation of $(9.6\pm0.2)$% 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.

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Anton Tamtögl, Michael Pusterhofer, Martin Bremholm, Ellen M. J. Hedegaard, Bo B. Iversen, Philip Hofmann, John Ellis, William Allison, S. Miret-Artés, Wolfgang E. Ernst. 2018-02-19. A Helium-Surface Interaction Potential of Bi$_2$Te$_3$(111) from Ultrahigh-Resolution Spin-Echo Measurements. https://doi.org/10.1016/j.susc.2018.02.006

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