Superfluid response in electron-doped cuprate superconductors

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.