Electronic structure, surface morphology, and topologically protected surface states of Sb2Te3 thin films grown on Si(111)
Electronic structure, surface morphology, and topologically protected surface states of Sb2Te3 thin films grown on Si(111)
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DOI：
10.1063/1.4789353
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发表时间：
2013-02-07
影响因子：
3.2
通讯作者：
Schneider, C. M.
中科院分区：
文献类型：
--
作者：
Plucinski, L.;Herdt, A.;Schneider, C. M.
We have performed a combined spectroscopy and microscopy study on surfaces of Sb2Te3/Si(111) thin films exposed to air and annealed under ultra-high vacuum conditions. Scanning tunneling microscopy images, with atomic resolution present in most areas of such processed surfaces, show a significant amount of impurities and defects. Scanning tunneling spectroscopy reveals the bulk band gap of similar to 170 meV centered similar to 65 meV above the Fermi level. This intrinsic p-type doping behavior is confirmed by high-resolution angle-resolved photoemission spectra, which show the dispersions of the lower Dirac cone and the spectral weight of the bulk valence bands crossing the Fermi level. Spin-polarized photoemission revealed up to similar to 15% in-plane spin polarization for photoelectrons related to the topologically protected Dirac cone states near the Fermi level, and up to similar to 40% for several states at higher binding energies. The results are interpreted using ab initio electronic structure simulations and confirm the robustness of the time-reversal symmetry protected topological surface states in Sb2Te3 in the presence of impurities and defects. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789353]
