Superfluid response in electron-doped cuprate superconductors

TL;DR

This paper introduces a two-band model with $d_{x^2-y^2}$ pairing symmetry to explain the unusual temperature dependence of superfluid density in electron-doped cuprate superconductors, unifying various experimental observations.

Contribution

It provides a novel two-band theoretical framework that accounts for the superfluid density behavior across temperatures in electron-doped cuprates, confirming $d_{x^2-y^2}$ pairing symmetry.

Findings

Explains upward curvature of superfluid density near $T_c$

Accounts for weak temperature dependence at low temperatures

Resolves experimental measurement discrepancies

Abstract

We propose a weakly coupled two-band model with $d_{x^2-y^2}$ pairing symmetry to account for the anomalous temperature dependence of superfluid density $\rho_s$ in electron-doped cuprate superconductors. This model gives a unified explanation to the presence of a upward curvature in $\rho_s$ near $T_c$ and a weak temperature dependence of $\rho_s$ in low temperatures. Our work resolves a discrepancy in the interpretation of different experimental measurements and suggests that the pairing in electron-doped cuprates has predominately $d_{x^2-y^2}$ symmetry in the whole doping range.