  A double-layered perovskite oxide Sr$_3$Mo$_2$O$_7$ is considered a "hidden
ladder" system with wide and narrow bands near the Fermi level, for which
high-$T_{\rm c}$ superconductivity is expected. However, the difficulty in
synthesis, especially in the preparation of samples without oxygen deficiency,
can hinder the observation of superconductivity. In this study, we constructed
a double-layer SrMoO$_3$ block through artificial superlattices with the
insulating SrTiO$_3$ block, (SrMoO$_3$)$_m$/(SrTiO$_3$)$_t$ ($m = 2, 4$; $t =
4$). First-principles calculations for bilayered SrMoO$_3$ ($m = 2$) exhibit a
wide-narrow band structure near the Fermi level, which bears a close
resemblance to Sr$_3$Mo$_2$O$_7$. The dispersion along the $k_z$ direction is
strongly suppressed by increasing the number of the SrTiO$_3$ layers, $t$.
However, no superconductivity is observed down to 0.1 K. We discuss the absence
of the superconductivity for the present films on the basis of results of
scanning transmission electron microscopy and band structure calculations.
