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Evidence for a Nodeless Gap from the Superfluid Density of Optimally Doped Pr_{1.855}Ce_{0.145}CuO_{4-y} Films

John A. Skinta·Thomas R. Lemberger·T. Greibe·M. Naito
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Abstract

We present measurements of the ab-plane magnetic penetration depth, λ(T), in five optimally doped Pr_{1.855}Ce_{0.145}CuO_{4-y} films for 1.6 K \leq T \leq T_c \sim 24 K. Low resistivities, high superfluid densities n_s(T)\propto λ^{-2}(T), high T_c's, and small transition widths are reproducible and indicative of excellent film quality. For all five films, λ^{-2}(T)/λ^{-2}(0) at low T is well fitted by an exponential temperature dependence with a gap, Δ_{min}, of 0.85 k_B T_c. This behavior is consistent with a nodeless gap and is incompatible with d-wave superconductivity.

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John A. Skinta, Thomas R. Lemberger, T. Greibe, M. Naito. 2002-05-07. Evidence for a Nodeless Gap from the Superfluid Density of Optimally Doped Pr_{1.855}Ce_{0.145}CuO_{4-y} Films. https://doi.org/10.1103/physrevlett.88.207003

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