  Iridate oxides display exotic physical properties that arise from the
interplay between a large spin-orbit coupling and electron correlations. Here,
we present a comprehensive study of the effects of hydrostatic pressure on the
electronic transport properties of SrIrO3 (SIO), a system that has recently
attracted a lot of attention as potential correlated Dirac semimetal. Our
investigations on untwinned thin films of SIO reveal that the electrical
resistivity of this material is intrinsically anisotropic and controlled by the
orthorhombic distortion of the perovskite unit cell. These effects provide
another evidence for the strong coupling between the electronic and lattice
degrees of freedom in this class of compounds. Upon increasing pressure, a
systematic increase of the transport anisotropies is observed. The anomalous
pressure-induced changes of the resistivity cannot be accounted for by the
pressure dependence of the density of the electron charge carriers, as inferred
from Hall effect measurements. Moreover, pressure-induced rotations of the IrO6
octahedra likely occur within the distorted perovskite unit cell and affect
electron mobility of this system.
