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Published on: August 2, 2019
Emergent superconductivity upon electron delocalization in layered nitride VCaN2 at ambient pressure
Lei Chen1, Meiyan Li1, Tianyu Zhai1
1College of Physics and Optoelectronic Technology, Baoji University of Arts and Sciences, Baoji, 721016, China. stonley@163.com.
Physical Chemistry Chemical Physics : PCCP
|August 6, 2026
Summary
We discovered VCaN2, a new layered nitride superconductor with a critical temperature up to 43 K at ambient pressure. This electride-derived material exhibits high-temperature superconductivity due to electron delocalization and strong electron-phonon coupling.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Quantum Phenomena
Background:
- Electrides, materials with localized interstitial anionic electrons (IAEs), are platforms for emergent quantum phenomena.
- Delocalization of IAEs can alter electronic properties and potentially induce superconductivity.
Purpose of the Study:
- To predict phonon-mediated superconductivity in VCaN2 using first-principles calculations.
- To investigate the role of V substitution in the electride WCaN2 on superconductivity.
Main Methods:
- First-principles calculations.
- Anisotropic Migdal-Eliashberg equations.
- Electronic localization function (ELF) calculations.
Main Results:
- Predicted phonon-mediated superconductivity in VCaN2 with a critical temperature (Tc) up to 43 K at ambient pressure.
- V substitution induced a band shift and depleted IAEs, leading to delocalized electronic states and metallicity.
- Strong electron-phonon coupling (λ = 1.217) was observed, primarily mediated by low-frequency V vibrational modes.
Conclusions:
- VCaN2 is a rare ambient-pressure nitride superconductor exceeding the McMillan limit.
- The study establishes VCaN2 as a promising material for high-Tc phonon-mediated superconductivity in layered electride-derived systems.
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