Fragility of Fermi arcs in Dirac semimetals

Abstract

We use tunable, vacuum ultraviolet laser-based angle-resolved photoemission spectroscopy and density functional theory calculations to study the electronic properties of Dirac semimetal candidate cubic PtBi${}_2$. In addition to bulk electronic states we also find surface states in PtBi${}_2$ which is expected as PtBi${}_2$ was theoretical predicated to be a candidate Dirac semimetal. The surface states are also well reproduced from DFT band calculations. Interestingly, the topological surface states form Fermi contours rather than double Fermi arcs that were observed in Na${}_3$Bi. The surface bands forming the Fermi contours merge with bulk bands in proximity of the Dirac points projections, as expected. Our data confirms existence of Dirac states in PtBi${}_2$ and reveals the fragility of the Fermi arcs in Dirac semimetals. Because the Fermi arcs are not topologically protected in general, they can be deformed into Fermi contours, as proposed by [Kargarian {\it et al.}, PNAS \textbf{113}, 8648 (2016)]. Our results demonstrate validity of this theory in PtBi${}_2$.

6 pages, 4 figures

References in corpus (6)

• Non-Abelian Anyons and Topological Quantum Computation
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Titanic Magnetoresistance in WTe2
• 3D Dirac semimetals: current materials, design principles and predictions of new materials
• Observation of Dirac surface states in the hexagonal PtBi2, a possible origin of the linear magnetoresistance
• Bulk and surface electronic structure of trigonal structured PtBi2 studied by angle-resolved photoemission spectroscopy

Cited by in corpus (2)

• Topological Semimetal Nanostructures: From Properties to Topotronics
• Type-II Dirac states in full Heusler compounds XInPd2 (X = Ti, Zr and Hf)