Towards an effective mass model for the quasi-1D magnesium diboride superconducting nanostructures

Abstract

We developed a parabolic effective mass model with the aim to describe the in-plane constricted superconductivity in few-monolayer MgB${}_2$. The model was employed to study a constricted quasi-$1$D superlattice with the simplest version of the Anderson approximation. Resonant Fano-Feshbach-like effect was found, between a miniband of a continuous normal state dispersion cutting across $E_F$ and a miniband of quasi-discrete dispersion, even though the latter is significantly energetically distanced from the Fermi level. The origin of the phenomenon was identified to be the presence of characteristic strongly localised eigenstates, due to the specific material parameters. Moreover, the mechanism leading to a "precursor" pseudogap region in a system with a non-zero phase difference is described, when the strength of the coupling is still not sufficient to open a superconducting gap, but enough to introduce electron-hole mixing into the system.

References in corpus (8)

• Resonant and crossover phenomena in a multiband superconductor tuning the chemical potential near a band edge
• The gap amplification at a "shape resonance" in a superlattice of quantum stripes: a mechanism for high Tc
• Evolution of multi-gap superconductivity in the atomically thin limit: Strain-enhanced three-gap superconductivity in monolayer MgB${}_2$
• Band-edge BCS-BEC crossover in a two-band superconductor: physical properties and detection parameters
• Superconducting transition temperature of Pb nanofilms: Impact of the thickness-dependent oscillations of the phonon mediated electron-electron coupling
• Gap Anisotropy in Multiband Superconductors Based on Multiple Scattering Theory
• Multigaps superconductivity at unconventional Lifshitz transition in a 3D Rashba heterostructure at atomic limit
• Room temperature superconductivity dome at a Fano resonance in superlattices of wires