Strong electron-phonon coupling and phonon-induced superconductivity in tetragonal C$_3$N$_4$ with hole doping
Autor: | Rudenko, Alexander N., Badrtdinov, Danis I., Abrikosov, Igor A., Katsnelson, Mikhail I. |
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Rok vydání: | 2023 |
Předmět: | |
Zdroj: | Phys. Rev. B 109, 014502 (2024) |
Druh dokumentu: | Working Paper |
DOI: | 10.1103/PhysRevB.109.014502 |
Popis: | C$_3$N$_4$ is a recently discovered phase of carbon nitrides with the tetragonal crystal structure [D.Laniel $\textit{et al.}$, Adv. Mater. 2023, 2308030] that is stable at ambient conditions. C$_3$N$_4$ is a semiconductor exhibiting flat-band anomalies in the valence band, suggesting the emergence of many-body instabilities upon hole doping. Here, using state-of-the-art first-principles calculations we show that hole-doped C$_3$N$_4$ reveals strong electron-phonon coupling, leading to the formation of a gapped superconducting state. The phase transition temperatures turn out to be strongly dependent on the hole concentration. We propose that holes could be injected into C$_3$N$_4$ via boron doping which induces, according to our results, a rigid shift of the Fermi energy without significant modification of the electronic structure. Based on the electron-phonon coupling and Coulomb pseudopotential calculated from first principles, we conclude that the boron concentration of 6 atoms per nm$^3$ would be required to reach the critical temperature of $\sim$36 K at ambient pressure. Comment: Calculation of the Coulomb pseudopotential revised, which lowered the predicted Tc. Final version: 10 pages incl. Supplemental Material, 10 figures, and 2 tables |
Databáze: | arXiv |
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