  In the search for high-temperature superconductivity in hydrides, a plethora
of multi-hydrogen superconductors have been theoretically predicted, and some
have been synthesized experimentally under ultrahigh pressures of several
hundred GPa. However, the impracticality of these high-pressure methods has
been a persistent issue. In response, we propose a new approach to achieve
high-temperature superconductivity under atmospheric pressure by implanting
hydrogen into lead to create a stable few-hydrogen metal-bonded perovskite,
Pb$_4$H. This approach diverges from the popular design methodology of
multi-hydrogen covalent high critical temperature ($T_c$) superconductors under
ultrahigh pressure. By solving the anisotropic Migdal-Eliashberg (ME)
equations, we demonstrate that perovskite Pb$_4$H is a typical phonon-mediated
superconductor with a $T_c$ of 46 K, which is six times higher than that of
bulk Pb (7.22 K) and higher than that of MgB$_2$ (39 K). The high $T_c$ can be
attributed to the strong electron-phonon coupling (EPC) strength of 2.45, which
arises from hydrogen implantation in lead that induces several high-frequency
optical phonon modes with a relatively large phonon linewidth resulting from H
atom vibration. The metallic-bonding in perovskite Pb$_4$H not only improves
the structural stability but also guarantees better ductility than the widely
investigated multi-hydrogen, iron-based, and cuprate superconductors. These
results suggest that there is potential for the exploration of new
high-temperature superconductors under atmospheric pressure and may reignite
interest in their experimental synthesis soon.
