Topological origin of the type-II Dirac fermions in PtSe2

Li Y, Xia Y, Ekahana SA, Kumar N, Jiang J, Yang L, Chen C, Liu C, Yan B, Felser C, Li G, Liu Z, Chen Y (2017)

Publication Type: Journal article

Publication year: 2017

Journal

Physical Review Materials American Physical Society

Book Volume: 1

Article Number: 074202

Journal Issue: 7

DOI: 10.1103/PhysRevMaterials.1.074202

Abstract

Group VIII transition-metal dichalcogenides have recently been proposed to host type-II Dirac fermions. They are Lorentz-violating quasiparticles marked by a strongly tilted conic dispersion along a certain momentum direction and therefore have no analogs in the standard model. Using high-resolution angle-resolved photoemission spectroscopy, we systematically studied the electronic structure of PtSe2 in the full three-dimensional Brillouin zone. As predicted, a pair of type-II Dirac crossings is experimentally confirmed along the kz axis. Interestingly, we observed conic surface states around time-reversal-invariant momenta Γ and M points. The signatures of nontrivial topology are confirmed by the first-principles calculation, which shows an intricate parity inversion of bulk states. Our discoveries not only contribute to a better understanding of topological band structure in PtSe2 but also help further explore the exotic properties, as well as potential application, of group VIII transition-metal dichalcogenides.

Involved external institutions

University of Oxford GB United Kingdom (GB) Pennsylvania State University (Penn State) US United States (USA) (US) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE) ShanghaiTech University / 上海科技大学 CN China (CN) Tsinghua University CN China (CN)

How to cite

APA:

Li, Y., Xia, Y., Ekahana, S.A., Kumar, N., Jiang, J., Yang, L.,... Chen, Y. (2017). Topological origin of the type-II Dirac fermions in PtSe2. Physical Review Materials, 1(7). https://doi.org/10.1103/PhysRevMaterials.1.074202

MLA:

Li, Yiwei, et al. "Topological origin of the type-II Dirac fermions in PtSe2." Physical Review Materials 1.7 (2017).

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