Temperature Dependent Gap Anisotropy from Interlayer Tunneling

TL;DR

This paper explains the temperature-dependent anisotropy of the superconducting gap in Bi-2212 using interlayer tunneling, revealing how different directions exhibit distinct temperature behaviors.

Contribution

It introduces a theoretical explanation for the observed anisotropic temperature dependence of the superconducting gap based on interlayer tunneling mechanisms.

Findings

Gap anisotropy varies with temperature along different crystallographic directions.

Superconducting gap along the Γ-M direction is less temperature-sensitive.

Gap along the Γ-X direction decreases rapidly with temperature.

Abstract

A recent experiment by Ma and collaborators shows that the gap anisotropy in ${\rm Bi}_2 {\rm Sr}_2 {\rm Ca}_1 {\rm Cu}_2 {\rm O}_{8+x}$ is strongly temperature dependent. In particular, the superconducting gap along the $\Gamma - M$ direction shows a weaker temperature dependence than the gap along the $\Gamma - X$ direction which decreases rapidly with temperature. We explain this novel feature as a natural consequence of the interlayer tunneling mechanism of superconductivity.