Comparative study of the compensated semi-metals LaBi and LuBi: a first-principles approach

Dey, Urmimala

doi:10.1088/1361-648x/aabc3d

Cited by 4 publications

(5 citation statements)

References 56 publications

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“…Calculating the parity products (δ n ) of the relevant bands at the TRIM points, we determine the Z 2 invariant for LaSb, LaBi and LaSb-LaBi heterostructure, as shown in Table 1. From Table 1, we find that LaBi 38,44 and LaSb/LaBi multilayer possess a non-trivial Z 2 topological invariant when we use both LDA and mBJLDA functionals, which is consistent with our (001) surface band structure calculations. However, in case of LaSb, inclusion of the mBJLDA functional changes the Z 2 index from 1 to 0, confirming that LaBi and LaSb-LaBi multilayer are topologically non-trivial, whereas, LaSb is topologically trivial with accidental Dirac cones on the (001) surface.…”

Section: Lasbsupporting

confidence: 83%

“…1. As seen, LaBi 38,44 and LaSb/LaBi heterostructure possess a non-trivial Z 2 index ν 0 = 1, indicating their non-trivial topological character. On the other hand, ν 0 changes from 1 to 0 for LaSb, when we introduce the mBJ potential, thus confirming the topologically trivial nature of LaSb.…”

Section: Calculation Of Z 2 Indexmentioning

confidence: 83%

“…In particular, we find that the Dirac point at the M-point in the Brillouin zone remains stable even when subjected to perturbations as long as the system remains time reversal invariant. Since LaBi is topologically non-trivial and possesses a non-zero Z 2 index, 38,44 the Dirac point at the surface is robust and remains stable when we change the c/a ratio in our slab calculations (Fig. 6(c)).…”

Section: Surface Band Structure Of Labimentioning

confidence: 98%

“…It has already been theoretically and experimentally verified that LaBi is a Z 2 semimetal with compensated electron and hole contributions 31,38,39,44 , while LaSb is topologically trivial but exhibits extremely large magnetoresistance 31,41 . Our mBJLDA+SO calculations reveal that their multilayer has a non-trivial topological character.…”

Section: /12mentioning

confidence: 99%

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Bulk band inversion and surface Dirac cones in LaSb and LaBi: Prediction of a new topological heterostructure

Dey

Chakraborty

Taraphder

et al. 2018

Sci Rep

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We perform ab initio investigations of the bulk and surface band structures of LaSb and LaBi and resolve the existing disagreements about the topological property of LaSb, considering LaBi as a reference. We examine the bulk band structure for band inversion, along with the stability of surface Dirac cones (if any) to time-reversal-preserving perturbations, as a strong diagnostic test for determining the topological character of LaSb, LaBi and LaSb-LaBi multilayer. A detailed ab initio investigation of a multilayer consisting of alternating unit cells of LaSb and LaBi shows the presence of band inversion in the bulk and a massless Dirac cone on the (001) surface, which remains stable under the influence of time-reversal-preserving perturbations, thus confirming the topologically non-trivial nature of the multilayer in which the electronic properties can be tailored as per requirement. A detailed invariant calculation is performed to arrive at a holistic conclusion.

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Section: Lasbsupporting

confidence: 83%

Section: Calculation Of Z 2 Indexmentioning

confidence: 83%

Section: Surface Band Structure Of Labimentioning

confidence: 98%

Section: /12mentioning

confidence: 99%

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Bulk band inversion and surface Dirac cones in LaSb and LaBi: Prediction of a new topological heterostructure

Dey

Chakraborty

Taraphder

et al. 2018

Sci Rep

Self Cite

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“…Recently, the family of rare earth monopnictides LnX (where, Ln is a rare earth element and X = As, Sb, Bi) have attracted great attention in the scientific community [1][2][3][4][5][6][7][8][9][10][11][12][13] because of having remarkable signatures of extremely large magnetoresistance (XMR) [3][4][5]7,9,10] and superconductivity [1,8]. Some LnX compounds like LaBi, CeBi, etc.…”

Section: Introductionmentioning

confidence: 99%

First principles investigation of topological phase in XMR material TmSb under hydrostatic pressure

Wadhwa

Kumar

Shukla

et al. 2019

J. Phys.: Condens. Matter

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In this article, we report emergence of topological phase in XMR material TmSb under hydrostatic pressure using first principles calculations. We find that TmSb, a topologically trivial semimetal, undergoes a topological phase transition with band inversion at X point without breaking any symmetry under a hydrostatic pressure of 12 GPa. At 15 GPa, it again becomes topologically trivial with band inversion at Γ as well as X point. We find that the pressures corresponding to the topological phase transitions are far below the pressure corresponding to structural phase transition at 25.5 GPa. The reentrant behaviour of topological quantum phase with hydrostatic pressure would help in finding a correlation between topology and XMR effect through experiments.

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Possible experimental realization of a basic Z2 topological semimetal in GaGeTe

et al. 2019

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We report experimental and theoretical evidence that GaGeTe is a basic Z2 topological semimetal with three types of charge carriers: bulk-originated electrons and holes as well as surface state electrons. This electronic situation is qualitatively similar to the primer 3D topological insulator Bi 2 Se 3 , but important differences account for an unprecedented transport scenario in GaGeTe. High-resolution angle-resolved photoemission spectroscopy combined with advanced band structure calculations show a small indirect energy gap caused by a peculiar band inversion in the T -point of the Brillouin zone in GaGeTe. An energy overlap of the valence and conduction bands brings both electron-and hole-like carriers to the Fermi level, while the momentum gap between the corresponding dispersions remains finite. We argue that peculiarities of the electronic spectrum of GaGeTe have a fundamental importance for the physics of topological matter and may boost the material's application potential.A variety of materials where topology of the electronic structure plays a special role in transport properties is rapidly growing [1][2][3]. The envisioned applications of topological materials in novel devices and quantum information technology will be strongly influenced by the fine balance between their charge carriers of various types. In classic 3D topological insulators, like Bi 2 Se 3 , the transport properties are dictated by the non-degenerate massless topological surface states as well as the electron-like carriers from the bulk conduction band [4]. In 3D Dirac or Weyl semimetals, the Fermi surface is formed by single points of band degeneration (type I), or hole and electronic pockets touching in discrete points (type II) [3]. A bulk material with a gapped electronic spectrum combining a comparable number of both types of the bulk charge carriers with the spin-momentum locked topological surface states has not yet been accounted for. Here we put forward GaGeTe as the first example of such conceptually different electronic situation, i. e. a basic Z 2 topological semimetal.The layered compound GaGeTe was first synthesized and structurally characterized quite long ago [5,6], and its phonon structure [7], thermoelectric [8] and transport [9] properties were consequently studied. However, the first theoretical study of its bulk electronic structure has appeared very recently [10] and has sparked strong interest in the surface electronic structure of this material [11]. In [10] structural and electronic resemblance between a structure fragment of the layered GaGeTe bulk and a heavy analogue of graphene, germanene [12], has been highlighted. 2D materials with buckled honeycomb atomic arrangements, e.g. silicene, germanene, stanene, are promising for the realization of new devices. For instance, silicene demonstrates such advantages as high carrier mobility, excellent mechanical flexibility and compatibility with existing Si-based electronics. Most recent studies establish theoretically [11] and experimentally [13] that monolayers...

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Comparative study of the compensated semi-metals LaBi and LuBi: a first-principles approach

Cited by 4 publications

References 56 publications

Bulk band inversion and surface Dirac cones in LaSb and LaBi: Prediction of a new topological heterostructure

Bulk band inversion and surface Dirac cones in LaSb and LaBi: Prediction of a new topological heterostructure

First principles investigation of topological phase in XMR material TmSb under hydrostatic pressure

Possible experimental realization of a basic Z2 topological semimetal in GaGeTe

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