Superconductivity in Alkali Metal-Deposited Monolayer BC: MBC (M = Na, K)

• Published in: Journal of low temperature physics 2024-12, Vol.217 (5-6), p.735-748
• Main Authors: Li, Ya-Ping, Yang, Liu, Liu, Hao-Dong, Shang, Shu-Ying, Chen, Ying-Jie
• Format: Article
• Language: English
• Subjects: Alkali metals; Characterization and Evaluation of Materials; Condensed Matter Physics; Coupling; Electronic structure; Electrons; First principles; Magnetic Materials; Magnetism; Monolayers; Physics; Physics and Astronomy; Superconductivity; Superconductors; Tensile strain; Transition temperature; Two dimensional materials; Vibration mode
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1007/s10909-024-03227-6

In recent years, as two-dimensional (2D) materials have been widely used in electronic devices, searching for 2D high superconducting transition temperature ( T c ) superconductors has also attracted great attentions. In this work, based on first-principles calculations and Eliashberg equation, the electronic structure, electron-phonon coupling (EPC) and possible superconductivity of alkali metal-deposited monolayer BC: M BC ( M = Na, K) are studied. The results show that M BC ( M = Na, K) are metallic and potential superconductors. The calculated EPC constants of M BC ( M = Na, K) are 0.97 and 1.48, respectively. The strong coupling of M BC ( M = Na, K) mainly origins from the coupling between electrons with the in-plane vibration modes of C and B atoms. The T c of M BC ( M  = Na, K) are 34.1 K and 41.7 K, respectively, and the T c of NaBC can be increased to 45.6 K under 2% biaxial tensile strain, and the T c of KBC can be boosted to 53.8 K under 1% biaxial tensile strain. It is anticipated that the predicted monolayer M BC ( M = Na, K) and its strained cases can be realized in future experiments.