  With octahedrally coordinated $t_{\rm 2g}$ orbitals which are active at
filling $n=2$, the $\rm Sr_2CrO_4$ compound exhibits rich interplay of
spin-orbital physics with tetragonal distortion induced crystal field tuning by
external agent such as pressure. Considering both reversed and restored crystal
field regimes, collective spin-orbital excitations are investigated in the
antiferromagnetic state using the generalized self consistent + fluctuations
approach including spin-orbit coupling (SOC). A transition is found from
staggered to entangled orbital order at critical SOC value in the realistic
regime. Behavior of the calculated energy scales of collective excitations with
crystal field is in striking similarity to that of the transition temperatures
with pressure as obtained from susceptibility and resistivity anomalies in
high-pressure studies.
