Multigap superconductivity in lithium intercalated bilayer Mo$_2$C

Fuente: arXiv
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Main Authors: Hong, Can, Wu, Danhong, Li, Xi-Bo, Zheng, Feipeng
Format: Preprint
Published: 2024
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author Hong, Can
Wu, Danhong
Li, Xi-Bo
Zheng, Feipeng
author_facet Hong, Can
Wu, Danhong
Li, Xi-Bo
Zheng, Feipeng
contents Interlayer coupling can significantly influence the physical properties of layered transition metal compounds. The superconductivity in layered Mo$_2$C systems, belonging to the emergent family of MXene, has garnered considerable attention. However, the impact of interlayer coupling on superconductivity, and the anisotropic superconducting properties in these systems are not yet clear. By performing first-principles calculations of electron-phonon coupling and anisotropic superconducting properties, we show that the interlayer coupling in bilayer 1$T$-Mo$_2$C suppresses superconductivity, resulting in a significant drop in superconducting transition temperature ($T_{\mathrm{c}}$) from 4.2 $K$ in its monolayer form to nearly 0 $K$. By introducing lithium atoms into the interlayer space of the bilayer, the interlayer coupling can be effectively weakened, transforming the system into a two-gap superconductor with a $T_{\mathrm{c}}$ above 10 $K$. A 3\% tensile strain can further transform the system into a three-gap superconductor with a significantly enhanced $T_{\mathrm{c}}$ of approximately 24.7 $K$, which is very high in the Mo$_2$C related systems. The enhancement of the superconductivity induced by the strain is mainly due to the downshift of an energy band with a flat dispersion to the energy near the Fermi level. The in-plane vibrations of Mo atoms and the $d$-orbital electrons of Mo atoms are most important for the formation of the superconductivity. Our method can also be applied to multilayer Mo$_2$C systems. Given the successful synthesis of layered Mo$_2$C systems and the experimental realization of alkaline metal atom depositions, our work presents a practically feasible strategy for achieving high $T_{\mathrm{c}}$ and multigap superconductivity in layered Mo$_2$C.
format Preprint
id arxiv_https___arxiv_org_abs_2402_13886
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Multigap superconductivity in lithium intercalated bilayer Mo$_2$C
Hong, Can
Wu, Danhong
Li, Xi-Bo
Zheng, Feipeng
Superconductivity
Materials Science
Interlayer coupling can significantly influence the physical properties of layered transition metal compounds. The superconductivity in layered Mo$_2$C systems, belonging to the emergent family of MXene, has garnered considerable attention. However, the impact of interlayer coupling on superconductivity, and the anisotropic superconducting properties in these systems are not yet clear. By performing first-principles calculations of electron-phonon coupling and anisotropic superconducting properties, we show that the interlayer coupling in bilayer 1$T$-Mo$_2$C suppresses superconductivity, resulting in a significant drop in superconducting transition temperature ($T_{\mathrm{c}}$) from 4.2 $K$ in its monolayer form to nearly 0 $K$. By introducing lithium atoms into the interlayer space of the bilayer, the interlayer coupling can be effectively weakened, transforming the system into a two-gap superconductor with a $T_{\mathrm{c}}$ above 10 $K$. A 3\% tensile strain can further transform the system into a three-gap superconductor with a significantly enhanced $T_{\mathrm{c}}$ of approximately 24.7 $K$, which is very high in the Mo$_2$C related systems. The enhancement of the superconductivity induced by the strain is mainly due to the downshift of an energy band with a flat dispersion to the energy near the Fermi level. The in-plane vibrations of Mo atoms and the $d$-orbital electrons of Mo atoms are most important for the formation of the superconductivity. Our method can also be applied to multilayer Mo$_2$C systems. Given the successful synthesis of layered Mo$_2$C systems and the experimental realization of alkaline metal atom depositions, our work presents a practically feasible strategy for achieving high $T_{\mathrm{c}}$ and multigap superconductivity in layered Mo$_2$C.
title Multigap superconductivity in lithium intercalated bilayer Mo$_2$C
topic Superconductivity
Materials Science
url https://arxiv.org/abs/2402.13886