%0 Journal Article
%A Nechaev, I. A.
%A Aguilera, I.
%A De Renzi, V.
%A di Bona, A.
%A Lodi Rizzini, A.
%A Mio, A. M.
%A Nicotra, G.
%A Politano, A.
%A Scalese, S.
%A Aliev, Z. S.
%A Babanly, M. B.
%A Friedrich, Christoph
%A Blügel, S.
%A Chulkov, E. V.
%T Quasiparticle spectrum and plasmonic excitations in the topological insulator Sb $_{2}$ Te $_{3}$
%J Physical review / B
%V 91
%N 24
%@ 1098-0121
%C College Park, Md.
%I APS
%M FZJ-2015-04370
%P 245123
%D 2015
%X We report first-principles GW results on the dispersion of the bulk band-gap edges in the three-dimensional topological insulator Sb2Te3. We find that, independently of the reference density-functional-theory band structure and the crystal-lattice parameters used, the one-shot GW corrections enlarge the fundamental band gap, bringing its value in close agreement with experiment. We conclude that the GW corrections cause the displacement of the valence-band maximum (VBM) to the Γ point, ensuring that the surface-state Dirac point lies above the VBM. We extend our study to the analysis of the electron-energy-loss spectrum (EELS) of bulk Sb2Te3. In particular, we perform energy-filtered transmission electron microscopy and reflection EELS measurements. We show that the random-phase approximation with the GW quasiparticle energies and taking into account virtual excitations from the semicore states leads to good agreement with our experimental data.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000355969300003
%R 10.1103/PhysRevB.91.245123
%U https://juser.fz-juelich.de/record/202081