Coexistence of type-II Dirac point and weak topological phase in 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Pt</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mi>Sn</mml:mi></mml:mrow></mml:math>

Kim, Min Soo; Wang, Cai Zhuang; Ho, Kai Ming

doi:10.1103/physrevb.96.205107

Cited by 7 publications

(4 citation statements)

References 46 publications

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“…One of the phases is shown to be a topological semi-metal with a band structure similar to that of HgTe 39 . Other examples include but are not limited to group V semi-metals 40 , HgCr 2 Se 4 41 , and Pt 3 Sn 42 . These semi-metallic materials with topological properties which is often due to a strong spin-orbit coupling also possess a small thermal conductivity due to the heavy mass of some of their constituents.…”

Section: Resultsmentioning

confidence: 99%

Semi-metals as potential thermoelectric materials

Markov

Liu

et al. 2018

Sci Rep

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The best thermoelectric materials are believed to be heavily doped semiconductors. The presence of a band gap is assumed to be essential to achieve large thermoelectric power factor and figure of merit. In this work, we propose semi-metals with large asymmetry between conduction and valence bands as an alternative class of thermoelectric materials. To illustrate the idea, we study semi-metallic HgTe in details experimentally and theoretically. We employ ab initio calculations with hybrid exchange-correlation functional to accurately describe the electronic band structure in conjunction with the Boltzmann Transport theory to investigate the electronic transport properties. We calculate the lattice thermal conductivity using first principles calculations and evaluate the overall figure of merit. To validate our theoretical approach, we prepare semi-metallic HgTe samples and characterize their transport properties. Our first-principles calculations agree well with the experimental data. We show that intrinsic HgTe, a semimetal with large disparity in its electron and hole masses, has a high thermoelectric power factor that is comparable to the best known thermoelectric materials. Finally, we propose other possible materials with similar band structures as potential candidates for thermoelectric applications.

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Section: Resultsmentioning

confidence: 99%

Semi-metals as potential thermoelectric materials

Markov

Liu

et al. 2018

Sci Rep

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“…Note that though Pt 3 Sn has features of topological insulators, there is a type-II Dirac node and significant bulk states appearing near the Fermi level around R point (Fig. 3c ), leading to the formation of a “weak topological insulator” (WTI) or topological semimetal 48 . The coexistence of topological surface states, Dirac fermion, and metallic bulk states in Pt 3 Sn constitutes a physical picture as it is consistent with our previous analysis of the competing contributions to MR that are associated with the angle between electric current and magnetic field.…”

Section: Resultsmentioning

confidence: 99%

“…Recently, binary Pt-Sn alloys have been identified as a new family of topological materials, which have five known stable phases of different compositions that show rich topological properties. Besides the PtSn 4 single crystal, which has already been demonstrated experimentally to be a nodal line Dirac semimetal 47 , a more interesting Pt 3 Sn alloy has been predicted theoretically to be a promising three-dimensional weak topological insulator hosting type-II Dirac fermion 48 . However, there is no experimental investigation of its topological properties and application in spintronic devices to-date.…”

Section: Introductionmentioning

confidence: 99%

Robust negative longitudinal magnetoresistance and spin–orbit torque in sputtered Pt3Sn and Pt3SnxFe1-x topological semimetal

et al. 2023

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Contrary to topological insulators, topological semimetals possess a nontrivial chiral anomaly that leads to negative magnetoresistance and are hosts to both conductive bulk states and topological surface states with intriguing transport properties for spintronics. Here, we fabricate highly-ordered metallic Pt3Sn and Pt3SnxFe1-x thin films via sputtering technology. Systematic angular dependence (both in-plane and out-of-plane) study of magnetoresistance presents surprisingly robust quadratic and linear negative longitudinal magnetoresistance features for Pt3Sn and Pt3SnxFe1-x, respectively. We attribute the anomalous negative longitudinal magnetoresistance to the type-II Dirac semimetal phase (pristine Pt3Sn) and/or the formation of tunable Weyl semimetal phases through symmetry breaking processes, such as magnetic-atom doping, as confirmed by first-principles calculations. Furthermore, Pt3Sn and Pt3SnxFe1-x show the promising performance for facilitating the development of advanced spin-orbit torque devices. These results extend our understanding of chiral anomaly of topological semimetals and can pave the way for exploring novel topological materials for spintronic devices.

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“…In contrast to the Pd analogies with several TNPs above E F , the valence bands are fully filled, so SOC leads to well separated bands around E F throughout the BZ. [38] SnPt 3 has been proposed as a weak topological insulator, [39] while PbPt 3 , with its additional complexities, will be discussed elsewhere. [38]…”

Section: Strain Effectsmentioning

confidence: 99%

Coexistence of triple nodal points, nodal links, and unusual flat bands in intermetallic APd3 ( A=Pb , Sn)

2018

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We investigate the electronic structure and several properties, and topological character, of the cubic time-reversal invariant intermetallic compounds PbPd3 and SnPd3 using density functional theory based methods. These compounds have a dispersionless band along the Γ − X line, forming the top of the Pd 4d bands and lying within a few meV of the Fermi level EF . Effects of the flat band on transport and optical properties have been inspected by varying the doping concentration treated with the virtual crystal approximation for substitution on the Pb site. In the absence of spin-orbit coupling (SOC), we find triple nodal points and three-dimensional nodal loops, which are known to lead to surface bands and drumhead states, respectively, which we discuss for PbPd3. SOC removes degeneracy in most of the zone, providing a topological index Z2=1 on the kz = 0 plane that indicates a topological character on that plane. The isovalent and isostructural compound SnPd3 shows only minor differences in its electronic structures, so it is expected to display similar electronic, transport, and topological properties.PACS numbers:

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Coexistence of type-II Dirac point and weak topological phase in Pt3Sn

Cited by 7 publications

References 46 publications

Semi-metals as potential thermoelectric materials

Semi-metals as potential thermoelectric materials

Robust negative longitudinal magnetoresistance and spin–orbit torque in sputtered Pt3Sn and Pt3SnxFe1-x topological semimetal

Coexistence of triple nodal points, nodal links, and unusual flat bands in intermetallic APd3 ( A=Pb , Sn)

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