Probing pairing symmetry of Sm_{1.85}Ce_{0.15}CuO_4 via highly-sensitive voltage measurements: Evidence for strong impurity scattering

Abstract

Using a highly-sensitive home-made mutual-inductance technique, temperature profiles of the magnetic penetration depth $\lambda (T)$ in the optimally-doped $S{m}_{1.85}C{e}_{0.15}Cu{O}_4$ thin films have been extracted. The low-temperature behavior of $\lambda (T)$ is found to be best-fitted by linear $\Delta \lambda (T)/\lambda (0)=\ln (2)k_{B}T/{\Delta }_0$ and quadratic $\Delta \lambda (T)/\lambda (0)={\Gamma }^{-1/2}{\Delta }_0^{-3/2}{T}^2$ laws above and below $T=0.22T_C$, respectively, which clearly indicates the presence of d-wave pairing mechanism dominated by strong paramagnetic scattering at the lowest temperatures. The best fits produce ${\Delta }_0/k_B{T}_C=2.07$ and $\Gamma /T_C=0.25(T_C/{\Delta }_0{)}^3$ for the estimates of the nodal gap parameter and impurity scattering rate.

References in corpus (1)

• Field-dependent diamagnetic transition in magnetic superconductor $S{m}_{1.85}C{e}_{0.15}Cu{O}_{4-y}$

Cited by in corpus (1)

• Possible manifestation of spin fluctuations in the temperature behavior of resistivity in Sm_{1.85}Ce_{0.15}CuO_4 thin films