  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.
