Conventional High-Temperature Superconductivity at Ambient Pressure in Zincblende-Like Light-Element Compounds.

To validate the feasibility of high-temperature superconductivity in light-element compounds at ambient pressure, we designed a class of XY4Z4 (Y4Z4 = B4N4, Si4C4, B4P4) structures based on the zincblende configuration. Using high-throughput calculations based on density functional theory, we evaluate 201 compounds and identify 17 materials that are both dynamically and mechanically stable at ambient pressure. These materials demonstrate an insulator-to-metal transition achieved through carrier doping, including 12 superconductors, with 4 of them showing a Tc above 20 K. Notably, LiB4N4 and MgB4P4 stand out with predicted Tc values of 67 and 45 K, respectively, both surpassing the Tc of MgB2. A high electronic density of states at the Fermi level, combined with phonon softening in the low-frequency region, enhances electron-phonon coupling strength. The exploration of strong-bond and lightweight materials will pave the way for achieving high-temperature superconductivity at ambient pressure.