GW study of topological insulators Bi2Se3, Bi2Te3, and Sb2Te3: Beyond the perturbative one-shot approach. Aguilera, I., Friedrich, C., Bihlmayer, G., & Blügel, S. Physical Review B, 88(4):045206, July, 2013.
GW study of topological insulators Bi2Se3, Bi2Te3, and Sb2Te3: Beyond the perturbative one-shot approach [link]Paper  doi  abstract   bibtex   
We present GW calculations of the topological insulators Bi2Se3, Bi2Te3, and Sb2Te3 within the all-electron full-potential linearized augmented-plane-wave formalism. Quasiparticle effects produce significant qualitative changes in the band structures of these materials when compared to density functional theory (DFT), especially at the Γ point, where band inversion takes place. There, the widely used perturbative one-shot GW approach can produce unphysical band dispersions, as the quasiparticle wave functions are forced to be identical to the noninteracting single-particle states. We show that a treatment beyond the perturbative approach, which incorporates the off-diagonal GW matrix elements and thus enables many-body hybridization to be effective in the quasiparticle wave functions, is crucial in these cases to describe the characteristics of the band inversion around the Γ point in an appropriate way. In addition, this beyond one-shot GW approach allows us to calculate the values of the Z2 topological invariants and compare them with those previously obtained within DFT.
@article{aguilera_gw_2013,
	title = {{GW} study of topological insulators {Bi2Se3}, {Bi2Te3}, and {Sb2Te3}: {Beyond} the perturbative one-shot approach},
	volume = {88},
	shorttitle = {{GW} study of topological insulators {Bi2Se3}, {Bi2Te3}, and {Sb2Te3}},
	url = {http://link.aps.org/doi/10.1103/PhysRevB.88.045206},
	doi = {10.1103/PhysRevB.88.045206},
	abstract = {We present GW calculations of the topological insulators Bi2Se3, Bi2Te3, and Sb2Te3 within the all-electron full-potential linearized augmented-plane-wave formalism. Quasiparticle effects produce significant qualitative changes in the band structures of these materials when compared to density functional theory (DFT), especially at the Γ point, where band inversion takes place. There, the widely used perturbative one-shot GW approach can produce unphysical band dispersions, as the quasiparticle wave functions are forced to be identical to the noninteracting single-particle states. We show that a treatment beyond the perturbative approach, which incorporates the off-diagonal GW matrix elements and thus enables many-body hybridization to be effective in the quasiparticle wave functions, is crucial in these cases to describe the characteristics of the band inversion around the Γ point in an appropriate way. In addition, this beyond one-shot GW approach allows us to calculate the values of the Z2 topological invariants and compare them with those previously obtained within DFT.},
	number = {4},
	urldate = {2015-11-06},
	journal = {Physical Review B},
	author = {Aguilera, Irene and Friedrich, Christoph and Bihlmayer, Gustav and Blügel, Stefan},
	month = jul,
	year = {2013},
	pages = {045206},
}

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