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arXiv · 1711.09637

Topological semimetals with nodal-rings and nexus fermions

Mighfar Imam·Ranjan Kumar Barik·Rinkle Juneja·Ravindra Shinde·Abhishek K. Singh
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Abstract

Based on the first-principles study, we report a new set of topological semimetals (TiS, TiSe, TiTe, HfS, HfSe, HfTe and ZrS) which show the co-existence of a nodal-ring and triply-degenerate points. The two-fold degenerate one-dimensional nodal ring structure in the bulk Brillouin zone exhibits the characteristic drumhead surface states. In addition to this, a peculiar band crossing along the $k_z$ direction takes place consisting of a point-crossing with three-fold band degeneracy. These triply-degenerate points give rise to "nexus" fermions as quasiparticles having no analogous elementary particle of the standard model. In this article, we simulate angle-resolved photoemission spectroscopy to obtain the exotic topological surface states and the characteristic Fermi arcs, and explain the evolution and separation of triple-points with the magnitude of spin-orbit coupling. This intermediate linearly dispersive degeneracy between Weyl and Dirac points may offer prospective candidates for quantum transport applications.

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Mighfar Imam, Ranjan Kumar Barik, Rinkle Juneja, Ravindra Shinde, Abhishek K. Singh. 2017-11-27. Topological semimetals with nodal-rings and nexus fermions. https://arxiv.org/abs/1711.09637

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