Observation of Weyl nodes in robust type-II Weyl semimetal WP2

Abstract

Distinct to type-I Weyl semimetals (WSMs) that host quasiparticles described by the Weyl equation, the energy dispersion of quasiparticles in type-II WSMs violates Lorentz invariance and the Weyl cones in the momentum space are tilted. Since it was proposed that type-II Weyl fermions could emerge from (W,Mo)Te2 and (W,Mo)P2 families of materials, a large numbers of experiments have been dedicated to unveil the possible manifestation of type-II WSM, e.g. the surface-state Fermi arcs. However, the interpretations of the experimental results are very controversial. Here, using angle-resolved photoemission spectroscopy supported by the first-principles calculations, we probe the tilted Weyl cone bands in the bulk electronic structure of WP2 directly, which are at the origin of Fermi arcs at the surfaces and transport properties related to the chiral anomaly in type-II WSMs. Our results ascertain that due to the spin-orbit coupling the Weyl nodes originate from the splitting of 4-fold degenerate band-crossing points with Chern numbers C = $\pm$2 induced by the crystal symmetries of WP2, which is unique among all the discovered WSMs. Our finding also provides a guiding line to observe the chiral anomaly which could manifest in novel transport properties.

13 pages, 3 figures

References in corpus (3)

• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Discovery of a new type of topological Weyl fermion semimetal state in Mo${}_x$W${}_{1-x}$Te${}_2$
• Surface Fermi arc connectivity in the type-II Weyl semimetal candidate WTe${}_2$

Cited by in corpus (16)

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• Gate-tunable Lifshitz transition of Fermi arcs and its nonlocal transport signatures
• Giant Chern number of a Weyl nodal surface without upper limit
• Room-Temperature Anisotropic Plasma Mirror and Polarization-Controlled Optical Switch Based on Type-II Weyl Semimetal WP2
• Strong nonlinear optical response and transient symmetry switching in Type-II Weyl semimetal $\beta$-WP2
• Highly anisotropic Drude-weight-reduction and enhanced linear-dichroism in van der Waals Weyl semimetal Td-MoTe2 with coherent interlayer electronic transport
• Lifshitz transitions and Weyl semimetals from a topological superconductor with supercurrent flow
• Conductance oscillation in surface junctions of Weyl semimetals
• Theory of universal differential conductance of magnetic Weyl type -II junctions
• Semiconducting Electronic Structure of the Ferromagnetic Spinel $\mathbf{Hg}{\mathbf{Cr}}_2{\mathbf{Se}}_4$ Revealed by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy
• Fano resonances in tilted Weyl semimetals in an oscillating quantum well
• Phonon Weyl points and chiral edge modes with unconventional Fermi arcs in NbSi${}_2$
• k-Resolved electronic structure of buried heterostructure and impurity systems by soft-X-ray ARPES