Berlin 2018 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 20: Topological Semimetals II
TT 20.7: Vortrag
Montag, 12. März 2018, 16:30–16:45, A 053
Generic Coexistence of Fermi Arcs and Dirac Cones on the Surface of Time-Reversal Invariant Weyl Semimetals — •Alexander Lau1, Klaus Koepernik2, Jeroen van den Brink2, and Carmine Ortix3 — 1Kavli Institute of Nanoscience, TU Delft, Netherlands — 2Institute for Theoretical Solid State Physics, IFW Dresden, Germany — 3Institute for Theoretical Physics, Utrecht University, Netherlands
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 Z2 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.