Magnetic ordering in RPtBi topological insulators from DFT+U calculations

Hallouche, A.; Hamri, A.; Kacimi, S.; Zaoui, A.

doi:10.1016/j.physb.2014.02.049

Cited by 12 publications

(5 citation statements)

References 22 publications

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“…Rare-earth (R) based ternary compounds RTX (T = Ni, Pd, Pt; X = Sb, Bi) belong to a large family of the so-called half-Heusler phases, which crystallize with a noncentrosymmetric cubic structure of the MgAgAs-type . A few of them are presently a subject of exceptional interest due to indications from ab initio electronic structure calculations of possible band inversion near the Fermi level and formation of a topologically nontrivial state, characterized by insulating band gap in their bulk, while having a gapless surface state that is protected by time-reversal symmetry. − The topology of the electronic bands in half-Heusler compounds is defined by so-called band inversion strength (BIS), Δ, defined as an energy difference between Γ 6 and Γ 8 energy levels at the Γ symmetry point in the Brillouin zone, i.e., Δ = Γ 6 – Γ 8 (note that in ref this is defined as Δ = Γ 8 – Γ 6 ). The compounds with positive values of Δ are topologically trivial, while those with negative Δ values are topologically nontrivial.…”

Section: Introductionmentioning

confidence: 99%

Band Inversion in Topologically Nontrivial Half-Heusler Bismuthides: ²⁰⁹Bi NMR Study

2015

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209Bi nuclear magnetic resonance (NMR) was measured in half-Heusler bismuthides ScPdBi, LuPdBi, and LuPtBi and discussed in conjunction with the NMR data recently reported for YPdBi and YPtBi. The observed 209Bi NMR spectra exhibit low intensity because of short nuclear transverse relaxation time (T 2) governed by sizable structural disorder. Remarkably, the NMR frequency shifts are positive for topologically trivial ScPdBi and YPdBi, yet strongly negative for topologically nontrivial YPtBi, LuPtBi, and LuPdBi with postulated inversion of the electronic bands near the Fermi level. For the former two compounds, the spin–lattice relaxation rate (1/T 1) is very large and seems correlated with the strength of spin–orbit coupling. The study demonstrates the capability of NMR spectroscopy to probe the band inversion in putative topological insulators.

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Section: Introductionmentioning

confidence: 99%

Band Inversion in Topologically Nontrivial Half-Heusler Bismuthides: ²⁰⁹Bi NMR Study

2015

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“…The energy difference between the Γ 8 and Γ 6 bands defines the band inversion strength, which is denoted by: ∆E = E Γ8 − E Γ 6 . Positive and negative values of ∆E confirm the topological non-trivial and trivial nature of the compounds [17,[29][30][31][32]. The calculated band inversion strength for TbPtBi compound is 1.23 eV.…”

Section: Effect Of Socmentioning

confidence: 55%

“…The lower energy of s-type orbital (−1.18 eV) than the p-type orbital (0.12 eV) caused due to the strong SOC describes the band-inversion. Because of the heavy elements present in the compound, the effective mass at the Fermi level is increased, reducing the energy of the s-type orbitals as a consequence [29][30][31]. This change in the band order, i.e.…”

Section: Effect Of Socmentioning

confidence: 99%

Tunable phase transitions in half-Heusler TbPtBi compound

Patel¹,

Sharma²,

Devanarayanan³

et al. 2022

J. Phys.: Condens. Matter

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We report various phase transitions in half-Heusler TbPtBi compound using Density Functional Theory (DFT). Specifically, the inclusion of spin-orbit coupling (SOC) leads to the band inversion resulting in the transition from the metallic to the topological semimetallic phase. However, in the presence of SOC, there is a phase transition from the topological semimetal to trivial semimetal when the material is subjected to compressive strain (<-7%). Subsequently, under the further increase of compressive strain (≥-7%), we find an opening of a direct band gap at the Γ point, driving the system from the trivial semimetallic to semiconducting state with changes in the sequence of the bands. In the absence of SOC, only the transition from the metallic to the semiconducting phase is noticed. Under tensile strain, the TbPtBi compound maintains its phase as in the unstrained condition but with an increase in the hole pocket at the Fermi level, both in the absence and presence of SOC. These tunable phase transitions (especially as a fraction of strain) make this compound very promising for application in various quantum devices such as highly sensitive strain gauges.

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“…The magnetic structure of GdPtBi was a subject of early ab initio calculations that, as was later discovered, failed to give the correct predictions [29,30]. The k = ( 1 2 10) structure was suggested as the lowest-energy one in [29], whereas the k = (100) phase was proposed in [30]. In both cases, the real structure was found to have a much higher energy.…”

Section: Discussionmentioning

confidence: 99%

Magnon spectrum of the Weyl semimetal half-Heusler compound GdPtBi

et al. 2020

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The compound GdPtBi is known as a material where the non-trivial topology of electronic bands interplays with an antiferromagnetic order, which leads to the emergence of many interesting magnetotransport phenomena. Although the magnetic structure of the compound has previously been reliably determined, the magnetic interactions responsible for this type of order remained controversial. In the present study, we employed time-of-flight inelastic neutron scattering to map out the low-temperature spectrum of spin excitations in single-crystalline GdPtBi. The observed spectra reveal two spectrally sharp dispersive spin-wave modes, which reflects the multi-domain state of the k = ( 1 2 1 2 1 2 ) face-centred cubic antiferromagnet in the absence of a symmetry-breaking magnetic field. The magnon dispersion reaches an energy of ∼ 1.1 meV and features a gap of ∼ 0.15 meV. Using linear spin-wave theory, we determined the main magnetic microscopic parameters of the compound that provide good agreement between the simulated spectra and the experimental data. We show that GdPtBi is well within the ( 1 2 1 2 1 2 ) phase and is dominated by second-neighbor interactions, thus featuring low frustration.

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Magnetic ordering in RPtBi topological insulators from DFT+U calculations

Cited by 12 publications

References 22 publications

Band Inversion in Topologically Nontrivial Half-Heusler Bismuthides: ²⁰⁹Bi NMR Study

Band Inversion in Topologically Nontrivial Half-Heusler Bismuthides: ²⁰⁹Bi NMR Study

Tunable phase transitions in half-Heusler TbPtBi compound

Magnon spectrum of the Weyl semimetal half-Heusler compound GdPtBi

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Magnetic ordering in RPtBi topological insulators from DFT+U calculations

Cited by 12 publications

References 22 publications

Band Inversion in Topologically Nontrivial Half-Heusler Bismuthides: 209Bi NMR Study

Band Inversion in Topologically Nontrivial Half-Heusler Bismuthides: 209Bi NMR Study

Tunable phase transitions in half-Heusler TbPtBi compound

Magnon spectrum of the Weyl semimetal half-Heusler compound GdPtBi

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Product

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Band Inversion in Topologically Nontrivial Half-Heusler Bismuthides: ²⁰⁹Bi NMR Study

Band Inversion in Topologically Nontrivial Half-Heusler Bismuthides: ²⁰⁹Bi NMR Study