Electronic structure in a transition metal dipnictide TaAs2

Abstract

The family of transition metal dipnictides (TMDs) has been of theoretical and experimental interest because this family hosts topological states and extremely large magnetoresistance (MR). Recently, TaAs2, a member of this family, has been predicted to support a topological crystalline insulating state. Here, by using high resolution. Angle resolved photoemission spectroscopy (ARPES), we reveal both closed and open pockets in the metallic Fermi surface and linearly dispersive bands on the (201) surface, along with the presence of extreme MR observed from magneto-transport measurements. A comparison of the ARPES results with first-principles computations show that the linearly dispersive bands on the measured surface of TaAs2 are trivial bulk bands. The absence of symmetry-protected surface state on the (201) surface indicates its topologically dark nature. The presence of open Fermi surface features suggests that the open orbit fermiology could contribute to the extremely large MR of TaAs.

13 pages, 5 figures

References in corpus (12)

• Topological Insulators with Inversion Symmetry
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Topological Crystalline Insulators
• Titanic Magnetoresistance in WTe2
• Gate-Tunable Negative Longitudinal Magnetoresistance in the Predicted Type-II Weyl Semimetal WTe2
• Anisotropic giant magnetoresistance in NbSb2
• Purely rotational symmetry-protected topological crystalline insulator $\alpha$-Bi4Br4
• Observation of Open-Orbit Fermi Surface Topology in Extremely Large Magnetoresistance Semimetal MoAs${}_2$
• Observation of gapped state in rare-earth monopnictide HoSb
• Topological crystalline insulator state with type-II Dirac fermions in transition metal dipnictides
• Magnetoresistance and Kondo effect in the nodal-line semimetal VAs${}_2$
• Electronic structure and open-orbit Fermi surface topology in isostructural semimetals NbAs${}_2$ and W${}_2$As${}_3$ with extremely large magnetoresistance