Applying experimental constraints to a one-dimensional model for BiS2 superconductivity

Abstract

Recent ARPES measurements [Phys. Rev. B 92, 041113 (2015)] have confirmed the one-dimensional character of the electronic structure of CeO0.5F0.5BiS2, a representative of BiS2-based superconductors. In addition, several members of this family present sizable increase in the superconducting transition temperature Tc under application of hydrostatic pressure. Motivated by these two results, we propose a one-dimensional three-orbital model, whose kinetic energy part, obtained through ab initio calculations, is supplemented by pair-scattering terms, which are treated at the mean-field level. We solve the gap equations self-consistently and then systematically probe which combination of pair-scattering terms gives results consistent with experiment, namely, a superconducting dome with a maximum Tc at the right chemical potential and a sizable increase in Tc when the magnitude of the hoppings is increased. For these constraints to be satisfied multi-gap superconductivity is required, in agreement with experiments, and one of the hoppings has a dominant influence over the increase of Tc with pressure.

4pages+references+supplemental material

References in corpus (10)

• Minimal electronic models for superconducting BiS${}_2$ layers
• Pressure-induced Enhancement of Superconductivity in BiS${}_2$-layered LaO${}_{1-x}$F${}_x$BiS${}_2$
• RPA Analysis of a Two-orbital Model for the BiS2-based Superconductors
• Superconducting materials classes: introduction and overview
• Unexpected Giant Superconducting Fluctuation and Anomalous Semiconducting Normal State in NdO1-xFxBi1-yS2 Single Crystals
• Electronic Structure of Single Crystalline NdO${}_{0.5}$F${}_{0.5}$BiS${}_2$ Studied by Angle-resolved Photoemission Spectroscopy
• Enhancement of superconductivity near the pressure-induced semiconductor-metal transition in BiS2-based compounds LnO(0.5)F(0.5)BiS2 (Ln = La, Ce, Pr, Nd)
• Fermi surfaces and orbital polarization in superconducting CeO${}_{0.5}$F${}_{0.5}$BiS${}_2$ revealed by angle-resolved photoemission spectroscopy
• Evidence for spin-triplet odd-parity superconductivity close to type-II van Hove singularities
• Mechanism for enhancement of superconductivity in multi-band systems with odd parity hybridization

Cited by in corpus (2)

• Strong bilayer coupling induced by the symmetry breaking in the monoclinic phase of BiS${}_2$-based superconductors
• Multiband superconductivity in $\mathrm{Bi}{\mathrm{S}}_2$-based layered compounds