Electronic properties of topological insulator candidate CaAgAs

Abstract

The topological phases of matter provide the opportunity to observe many exotic properties, like the existence of two dimensional topological surface states in the form of Dirac cone in topological insulators, chiral transport through open Fermi arc in Weyl semimetals etc. However, these properties can only affect the transport characteristics and therefore can be useful for applications only if the topological phenomena occur near the Fermi level. CaAgAs is a promising candidate, wherein the ab-initio calculations predict line-node at the Fermi level which on including spin-orbit coupling transforms into a topological insulator. In this report, we study the electronic structure of CaAgAs with angle resolved photoemission spectroscopy (ARPES), ab-initio calculations and transport measurements. The ARPES results show that the bulk valence band crosses the Fermi energy at gamma-point and the band dispersion matches the ab-initio calculations closely on shifting the Fermi energy by -0.5 eV. ARPES results are in good agreement with our transport measurements which show abundant p-type carriers.

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Cited by in corpus (10)

• Topological Semimetals from first-principles
• Topological transport in Dirac nodal-line semimetals
• Topological Hall effect in the antiferromagnetic Dirac semimetal EuAgAs
• Trivial topological phase of CaAgP and the topological nodal-line transition in CaAg(P1-xAsx)
• Quantum oscillations probe the Fermi surface topology of the nodal-line semimetal CaAgAs
• Weak antilocalization effect and triply degenerate state in Cu-doped CaAuAs
• High-Mobility Carriers Induced by Chemical Doping in the Candidate Nodal-Line Semimetal CaAgP
• Real spin and pseudospin topologies in the noncentrosymmetric topological nodal-line semimetal CaAgAs
• Drumhead surface states and their signatures in quasiparticle scattering interference
• Synthesis of europium-based crystals containing As or P by a flux method: attempts to grow EuAgP single crystals