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arXiv · 1701.01660

Generic coexistence of Fermi arcs and Dirac cones on the surface of time-reversal invariant Weyl semimetals

Alexander Lau·Klaus Koepernik·Jeroen van den Brink·Carmine Ortix
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Abstract

The hallmark of Weyl semimetals is the existence of open constant-energy contours on their surface -- the so-called Fermi arcs -- connecting Weyl points. Here, we show that for time-reversal symmetric realizations of Weyl semimetals these Fermi arcs in many cases coexist with closed Fermi pockets originating from surface Dirac cones pinned to time-reversal invariant momenta. The existence of Fermi pockets is required for certain Fermi-arc connectivities due to additional restrictions imposed by the six $\mathbb{Z}_2$ topological invariants characterizing a generic time-reversal invariant Weyl semimetal. We show that a change of the Fermi-arc connectivity generally leads to a different topology of the surface Fermi surface, and identify the half-Heusler compound LaPtBi under in-plane compressive strain as a material that realizes this surface Lifshitz transition. We also discuss universal features of this coexistence in quasi-particle interference spectra.

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Alexander Lau, Klaus Koepernik, Jeroen van den Brink, Carmine Ortix. 2017-08-18. Generic coexistence of Fermi arcs and Dirac cones on the surface of time-reversal invariant Weyl semimetals. https://doi.org/10.1103/physrevlett.119.076801

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