Enhanced superconductivity in two-dimensional <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>Cu</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:mi mathvariant="normal">N</mml:mi> </mml:mrow> </mml:math> : First-p
Two-dimensional materials with intrinsic superconductivity and nontrivial topology represent a frontier for discovering exotic quantum states and potential applications in quantum devices. Here, we report the first comprehensive theoretical investigation of superconductivity in monolayer and bilayer ${\mathrm{Cu}}_{2}\mathrm{N}$. The monolayer ${\mathrm{Cu}}_{2}\mathrm{N}$ has been recently synthesized experimentally and features a unique checkerboard lattice with topological nodal lines. Following this experimental breakthrough, we predict phonon-mediated superconductivity with transition temperatures (${T}_{c}$) of 3.8 K (monolayer) and 7.9 K (bilayer) arising from strong electron-phonon coupling ($\ensuremath{\lambda}=0.76$ and 0.84, respectively) mediated primarily by Cu $d$-orbitals and low-frequency phonon modes. The bilayer shows 84% ${T}_{c}$ enhancement through additional interlayer vibrational modes that strengthen Cu $d$-orbital coupling via enhanced out-of-plane vibrations. Strain engineering enhances monolayer ${T}_{c}$ to 4.5 K under 0.2% compressive strain through optimized electronic density of states and phonon softening. We identify a practical synthesis pathway involving multilayer growth followed by controlled exfoliation with moderate energy cost ($0.97{\mathrm{J}/\mathrm{m}}^{2}$). Our results demonstrate that ${\mathrm{Cu}}_{2}\mathrm{N}$, featuring coexisting topological nodal lines and phonon-mediated superconductivity, represents a promising experimental platform for investigating potential topological superconducting behavior in accessible two-dimensional systems.
Authors
- Guangren Na
- Meng‐hui Wang
- Zhong‐hua Cui (ORCID: https://orcid.org/0000-0002-0710-1774)
- Bian Rui
Institutions
- Jilin University (CN)
- Jilin Medical University (CN)
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry
Publication Details
- Journal
- Physical review. B./Physical review. B
- Published
- 2025-11-04
- DOI
- https://doi.org/10.1103/t7nc-p31n
- Primary Topic
- Topological Materials and Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00