Can the noble metals (Au, Ag and Cu) be superconductors?

Abstract

It is common knowledge that noble metals are excellent conductors but do not exhibit superconductivity. On the other hand, quantum confinement in thin films has been consistently shown to induce a significant enhancement of the superconducting critical temperature in several superconductors. It is therefore an important fundamental question whether ultra-thin film confinement may induce observable superconductivity in non-superconducting metals. We present a generalization, in the Eliashberg framework, of a BCS theory of superconductivity in good metals under thin-film confinement. By numerically solving these new Eliashberg-type equations, we find the dependence of the superconducting critical temperature on the film thickness $L$. This parameter-free theory predicts a maximum increase in the critical temperature for a specific value of the film thickness, which is a function of the number of free carriers in the material. Exploiting this fact, we predict that ultra-thin films of gold, silver and copper of suitable thickness could be superconductors at low but experimentally accessible temperatures. We demonstrate that this is a fine-tuning problem where the thickness must assume a very precise value, close to half a nanometer.

arXiv commentCorrected typo in the formula which defines C'

References in corpus (10)

• EPW: Electron-phonon coupling, transport and superconducting properties using maximally localized Wannier functions
• Anisotropic Migdal-Eliashberg theory using Wannier functions
• Assembling the puzzle of superconducting elements: A Review
• Threefold enhancement of superconductivity and the role of field-induced odd-frequency pairing in epitaxial aluminum films near the 2D limit
• Breakdown of Migdal's theorem and intensity of electron-phonon coupling in high-Tc superconductors
• The ${\omega }^3$ scaling of the vibrational density of states in quasi-2D nanoconfined solids
• Rise and fall of shape resonances in thin films of BCS superconductors
• Analysis of the London penetration depth in Ni-doped CaKFe4As4
• Extended analytical BCS theory of superconductivity in thin films
• Effective Theory of Superconductivity in Strongly-Coupled Amorphous Materials

Cited by in corpus (7)

• Quantum confinement theory of ultra-thin films: electronic, thermal and superconducting properties
• Revealing Symmetry-Broken Superconducting Configurations by Density Functional Theory
• Bending-strain effects in conventional superconductors and superconducting junctions
• Microscopic mechanism of electric field-induced superconductivity suppression in metallic thin films
• Turning non-superconducting elements into superconductors by quantum confinement and proximity
• Ginzburg-Landau Theory for Confined Thin-Film Superconductors
• Enhanced superconductivity in atomically thin noble metals: From quantum confinement to interface-induced Lifshitz transition