  We report on the synthesis and transport properties of perovskite (Pv) CaIrO3
thin films. The Pv phase of CaIrO3 was stabilized by epitaxial growth on
SrTiO3, (LaAlO3)0.3(Sr2AlTaO6)0.7, and LaAlO3 substrates with strong tensile,
weak tensile, and compressive strains, respectively. The resistivity of these
films showed a poorly metallic behavior. The Hall resistivity exhibited a sign
change as a function of temperature and a nonlinear magnetic-field dependence,
which clearly indicated the coexistence of electrons and holes and hence
supported that Pv CaIrO3 films are semimetallic. The observed robustness of the
semimetallic ground state against tensile and compressive strains is consistent
with the presence of symmetry-protected Dirac points (nodes) around the Fermi
level that prohibits the system from becoming a band insulator.
