Polarization-resolved resonant Raman excitation of surface and bulk electronic bands and phonons in MBE-grown topological insulator thin films.

Interaction of phonons with Dirac-like electronic states sets the fundamental limit of electron transport in topological insulators (TIs). Polarization-resolved and resonant Raman scattering of bulk and surface electronic excitation and vibrational modes in BiTe and BiSbTeSe (BSTS) thin films was investigated. At photon energies () of 1.

Electron-driven processes in enantiomeric forms of glutamic acid initiated by low-energy resonance electron attachment.

Low-energy (0-14 eV) resonance electron interaction and fragment species produced by dissociative electron attachment (DEA) for enantiomeric forms of glutamic acid (Glu) are studied under gas-phase conditions by means of DEA spectroscopy and density functional theory calculations. Contrary to a series of amino acids studied earlier employing the DEA technique, the most abundant species are not associated with the elimination of a hydrogen atom from the parent molecular negative ion. Besides this less intense closed-shell [Glu - H]- fragment, only two mass-selected negative ions, [Glu - 19]- and [Glu - 76]-, are detected within the same electron energy region, with the yield maximum observed at around 0.

Raman scattering spectroscopy of MBE grown thin film topological insulator BiSbTeSe.

BSTS epitaxial thin film topological insulators were grown using the MBE technique on two different types of substrates , Si (111) and SiC/graphene with BiSbTeSe and BiSbTeSe, respectively. The crystallographic properties of BSTS films were investigated X-ray diffraction, which showed the strongest reflections from the (0 0 ) facets corresponding to the rhombohedral phase. Superior epitaxial growth, homogeneous thickness, smooth surfaces, and larger unit cell parameters were observed for the films grown on the Si substrate.