Enhanced superconductivity in atomically thin noble metals: From quantum confinement to interface-induced Lifshitz transition

Abstract

Unlocking superconductivity in intrinsically non-superconducting noble metals (Au, Ag, Cu) represents a fundamental challenge in low-dimensional physics. While quantum confinement in the atomically thin limit is known to trigger emergent superconductivity, strategies to amplify this marginal effect to experimentally accessible temperatures remain a key open question. Using first-principles calculations, we establish a unified framework linking intrinsic confinement effects with interface engineering in noble metal films. We reveal that intrinsic superconductivity is element-specific: it is suppressed in Ag by a stiff phonon spectrum, but emerges in trilayer Cu ($T_{\mathrm{C}}\approx 0.78$ K) and pentalayer Au ($0.63$ K) driven by confinement-induced density-of-states (DOS) enhancement and phonon softening, respectively. In h-BN/Cu(111) heterostructures, $T_{\mathrm{C}}$ is critically dictated by the interfacial stacking configuration. We identify the thermodynamically stable N-bonded interface as a reliable platform for accessible superconductivity ($T_{\mathrm{C}}\approx 3.23$ K), whereas manipulating the system into a metastable B-bonded configuration boosts $T_{\mathrm{C}}$ to $7.00$ K. This enhancement originates from a B-bonded-induced Lifshitz transition, where the Fermi surface forms a tangential contact with the Brillouin zone boundary at the M point, enhancing electron-phonon coupling beyond DOS effects. Our work unifies the understanding of intrinsic two-dimensional superconductivity with atomistic interface design, offering a blueprint for functionalizing noble metals as emergent superconductors.

13 pages, 6 figures

References in corpus (25)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Phonons and related properties of extended systems from density-functional perturbation theory
• Boron nitride substrates for high-quality graphene electronics
• Wannier90: A Tool for Obtaining Maximally-Localised Wannier Functions
• Quantum sensing
• Maximally-localized Wannier functions for entangled energy bands
• Electron-phonon interactions from first principles
• EPW: Electron-phonon coupling, transport and superconducting properties using maximally localized Wannier functions
• Nanoporous Metals: From Plasmonic Properties to Applications in Enhanced Spectroscopy and Photocatalysis
• Ab initio model of optical properties of two-temperature warm dense matter
• Single Flux Quantum-Based Digital Control of Superconducting Qubits in a Multi-Chip Module
• Observation of Interface Superconductivity in a SnSe2-Epitaxial Graphene van der Waals Heterostructure
• Superconductivity in the surface state of noble metal gold and its Fermi level tuning by EuS dielectric
• Extended analytical BCS theory of superconductivity in thin films
• Ab initio determination of effective electron-phonon coupling factor in copper
• On the engineering of higher-order Van Hove singularities in two dimensions
• Theory of superconductivity in thin films under an external electric field
• Two-band superconductivity of bulk and surface states in Ag thin films on Nb
• Ferroelectric tuning of superconductivity and band topology in a two-dimensional heterobilayer
• Engineering ultra-strong electron-phonon coupling and nonclassical electron transport in crystalline gold with nanoscale interfaces
• Can the noble metals (Au, Ag and Cu) be superconductors?
• Quantum phase transition in two-dimensional NbN superconducting thin films
• Intriguing electronic and optical prospects of FCC bimetallic two-dimensional heterostructures: epsilon near-zero behaviour in UV-vis range
• Role of interface hybridization on induced superconductivity in 1T${}^{\prime }$-WTe${}_2$ and 2H-NbSe${}_2$ heterostructures
• Turning non-superconducting elements into superconductors by quantum confinement and proximity