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.

Quasiparticle spectrum and plasmonic excitations in the topological insulator Sb2Te3 / Nechaev, I. A.; Aguilera, I.; De Renzi, Valentina; Di Bona, A.; Lodi Rizzini, Alberto; Mio, A. M.; Nicotra, G.; Politano, A.; Scalese, S.; Aliev, Z. S.; Babanly, M. B.; Friedrich, C.; Blügel, S.; Chulkov, E. V.. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - ELETTRONICO. - 91:24(2015), pp. 1-8. [10.1103/PhysRevB.91.245123]

Quasiparticle spectrum and plasmonic excitations in the topological insulator Sb2Te3

DE RENZI, Valentina;LODI RIZZINI, ALBERTO;
2015

Abstract

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.
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Quasiparticle spectrum and plasmonic excitations in the topological insulator Sb2Te3 / Nechaev, I. A.; Aguilera, I.; De Renzi, Valentina; Di Bona, A.; Lodi Rizzini, Alberto; Mio, A. M.; Nicotra, G.; Politano, A.; Scalese, S.; Aliev, Z. S.; Babanly, M. B.; Friedrich, C.; Blügel, S.; Chulkov, E. V.. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - ELETTRONICO. - 91:24(2015), pp. 1-8. [10.1103/PhysRevB.91.245123]
Nechaev, I. A.; Aguilera, I.; DE RENZI, Valentina; Di Bona, A.; LODI RIZZINI, Alberto; Mio, A. M.; Nicotra, G.; Politano, A.; Scalese, S.; Aliev, Z. S.; Babanly, M. B.; Friedrich, C.; Blügel, S.; Chulkov, E. V.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11380/1118462
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