TY  - JOUR
AU  - Nechaev, I. A.
AU  - Aguilera, I.
AU  - De Renzi, V.
AU  - di Bona, A.
AU  - Lodi Rizzini, A.
AU  - Mio, A. M.
AU  - Nicotra, G.
AU  - Politano, A.
AU  - Scalese, S.
AU  - Aliev, Z. S.
AU  - Babanly, M. B.
AU  - Friedrich, Christoph
AU  - Blügel, S.
AU  - Chulkov, E. V.
TI  - Quasiparticle spectrum and plasmonic excitations in the topological insulator Sb $_{2}$ Te $_{3}$
JO  - Physical review / B
VL  - 91
IS  - 24
SN  - 1098-0121
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2015-04370
SP  - 245123
PY  - 2015
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000355969300003
DO  - DOI:10.1103/PhysRevB.91.245123
UR  - https://juser.fz-juelich.de/record/202081
ER  -