Anton Tamtögl

Continuous Compressed Sensing for Surface Dynamical Processes with Helium Atom Scattering.

Compressed Sensing (CS) techniques are used to measure and reconstruct surface dynamical processes with a helium spin-echo spectrometer for the first time. Helium atom scattering is a well established method for examining the surface structure and dynamics of materials at atomic sized resolution and the spin-echo technique opens up the possibility of compressing the data acquisition process. CS methods demonstrating the compressibility of spin-echo spectra are presented for several measurements. Recent developments on structured multilevel sampling that are empirically and theoretically shown to substantially improve upon the state of the art CS techniques are implemented. In addition, wavelet based CS approximations, founded on a new continuous CS approach, are used to construct continuous spectra. In order to measure both surface diffusion and surface phonons, which appear usually on different energy scales, standard CS techniques are not sufficient. However, the new continuous CS wavelet approach allows simultaneous analysis of surface phonons and molecular diffusion while reducing acquisition times substantially. The developed methodology is not exclusive to Helium atom scattering and can also be applied to other scattering frameworks such as neutron spin-echo and Raman spectroscopy.

Electron-phonon coupling and surface Debye temperature of Bi2Te3(111) from helium atom scattering

We have studied the topological insulator Bi

Note: A simple sample transfer alignment for ultra-high vacuum systems

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A Helium-Surface Interaction Potential of Bi2Te3(111) from Ultrahigh-Resolution Spin-Echo Measurements

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Ballistic Diffusion in Poly-aromatic Hydrocarbons on Graphite

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Ballistic Diffusion in Polyaromatic Hydrocarbons on Graphite

(111) by means of helium atom scattering. The average electron-phonon coupling

Atomic-Scale Diffusion and Friction on a Topological Insulator Surface: H2O on Bi2Te3(111)

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Adsorption Properties of Hydrogen on Antimony (111) Probed by Helium Atom Scattering

of Bi

Surface dynamics and atom-surface interaction of topological insulators from helium atom scattering

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Diffusion on a topological insulator surface: H2O on Bi2Te3(111)

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