Effect of hydrostatic pressure and uniaxial strain on the electronic structure of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Pb</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Sn</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:mi>Te</mml:mi></mml:mrow></mml:math>

Geilhufe, R. Matthias; Nayak, Sanjeev K.; Thomas, Stefan; Däne, M.; Tripathi, G. S.; Entel, P.; Hergert, W.; Ernst, A.

doi:10.1103/physrevb.92.235203

Cited by 19 publications

(9 citation statements)

References 59 publications

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“…8, as in Ref. 64 , where w is the average contribution of a type of atom for a given orbital to the band. For example, w(Bi p ) is the weight of p-orbital of Bi atom in a specific band.…”

Section: Electronic Propertiesmentioning

confidence: 99%

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First-principles modeling of binary layered topological insulators: Structural optimization and exchange-correlation functionals

et al. 2020

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Topological insulators (TIs) are materials that are insulating in the bulk but have zero band gap surface states with linear dispersion and are protected by time reversal symmetry. These unique characteristics could pave the way for many promising applications that include spintronic devices and quantum computations. It is important to understand and theoretically describe TIs as accurately as possible in order to predict properties. Quantum mechanical approaches, specifically first principles density functional theory (DFT) based methods, have been used extensively to model electronic properties of TIs. Here, we provide a comprehensive assessment of a variety of DFT formalisms and how these capture the electronic structure of TIs. We concentrate on Bi2Se3 and Bi2Te3 as examples of prototypical TI materials. We find that the generalized gradient (GGA) and kinetic density functional (metaGGA) produce displacements increasing the thickness of the TI slab, whereas we see an opposite behavior in DFT computations using LDA. Accounting for van der Waals (vdW) interactions overcomes the apparent over-relaxations and retraces the atomic positions towards the bulk. Based on an intensive computational study, we show that GGA with vdW treatment is the most appropriate method for structural optimization. Electronic structures derived from GGA or metaGGA employing experimental lattice parameters are also acceptable. In this regard, we express a slight preference for metaGGA in terms of accuracy, but an overall preference for GGA due to compensatory improvements in computability in capturing TI behavior.

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“…8, as in Ref. 64 , where w is the average contribution of a type of atom for a given orbital to the band. For example, w(Bi p ) is the weight of p-orbital of Bi atom in a specific band.…”

Section: Electronic Propertiesmentioning

confidence: 99%

“…The parity is calculated with the algorithm taken from Ref. 64 (see Fig. 8, stated for Bi 2 Se 3 as an example).…”

Section: Electronic Propertiesmentioning

confidence: 99%

First-principles modeling of binary layered topological insulators: Structural optimization and exchange-correlation functionals

et al. 2020

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“…1,5,6 Experimentally, the TCI surface states were observed by angle-and spin-resolved photoemission electron spectroscopy [2][3][4]7 , scanning tunneling microscopy/spectroscopy 8 , magnetotransport and magnetooptical quantum oscillatory effects. [9][10][11] The band inversion and topological transition in Pb 1−x Sn x Te was recently analyzed theoretically by ourselves 12 and others 6,[13][14][15] using the density functional theory (DFT), the tight binding approximation (TBA), the virtual crystal approximation (VCA), and the method of special quasirandom structures (SQS) developed 16 for the analysis of substitutional alloys. Confirming the successful basic picture obtained in early VCA calculations 6 the other methods accounted for local chemical disorder, inevitably present in alloys.…”

Section: Introductionmentioning

confidence: 99%

Band structure and topological phases of Pb$_{1-x-y}$Sn$_x$Mn$_y$Te by ab initio calculations

Łusakowski,

Bogusławski,

Story

2020

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The change in the composition of Pb1−xSnxTe IV-VI semiconductor or in its lattice parameter can drive a transition from the topologically trivial to the topological crystalline insulator (TCI), crossing a region where the alloy is in the Weyl semimetal phase. Incorporation of the magnetic Mn ions induces strong perturbations of the electronic structure, which act on both orbital and spin variables. Our first principles calculations show that the presence of Mn shifts the TCI and the Weyl region towards higher Sn contents in Pb1−xSnxTe. When the Mn spin polarization is finite, the spin perturbation, like the orbital part, induces changes in band energies comparable to the band gap, which widens the Weyl area. The effect opens a possibility of driving transitions between various topological phases of the system by magnetic field or by the spontaneous Mn magnetization. We also propose a new method to calculate topological indices for systems with a finite spin polarization defined based on the concept of the Chern number. These valid topological characteristics enable an identification of the three distinct topological phases of the Pb1−x−ySnxMnyTe alloy.

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“…Among the most prominent examples are the two-dimensional material graphene [2], bulk topological insulators [3] such as Pb x Sn 1−x Te [4][5][6] or Bi 2 Se 3 [7][8][9] hosting massless Dirac fermions on the surface and Weyl semimetals such as TaAs [10,11].…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional organic Dirac-line materials due to nonsymmorphic symmetry: A data mining approach

et al. 2017

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A data mining study of electronic Kohn-Sham band structures was performed to identify Dirac materials within the Organic Materials Database (OMDB). Out of that, the three-dimensional organic crystal 5,6-bis(trifluoromethyl)-2-methoxy-1H-1,3-diazepine was found to host different Dirac line-nodes within the band structure. From a group theoretical analysis, it is possible to distinguish between Dirac line-nodes occurring due to twofold degenerate energy levels protected by the monoclinic crystalline symmetry and twofold degenerate accidental crossings protected by the topology of the electronic band structure. The obtained results can be generalized to all materials having the space group P 21/c (No. 14, C 5 2h ) by introducing three distinct topological classes.

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Effect of hydrostatic pressure and uniaxial strain on the electronic structure ofPb1−xSnxTe

Cited by 19 publications

References 59 publications

First-principles modeling of binary layered topological insulators: Structural optimization and exchange-correlation functionals

First-principles modeling of binary layered topological insulators: Structural optimization and exchange-correlation functionals

Band structure and topological phases of Pb$_{1-x-y}$Sn$_x$Mn$_y$Te by ab initio calculations

Three-dimensional organic Dirac-line materials due to nonsymmorphic symmetry: A data mining approach

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