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Muon Spin Relaxation Measurements in Na_xCoO_2*yH_2O

A. Kanigel·A. Keren·L. Patlagan·K. B. Chashka·B. Fisher·P. King·A. Amato
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Abstract

Using the transverse field muon spin relaxation technique we measure the temperature dependence of the magnetic field penetration depth $λ$, in the Na$_{x}$CoO$_{2}\cdot y$H$_{2}$O system. We find that $λ,$ which is determined by superfluid density $n_{s}$ and the effective mass $m^{\ast}$, is very small and on the edge of the TF-$μ$SR sensitivity. Nevertheless, the results indicate that the order parameter in this system has nodes and that it obeys the Uemura relation. By comparing $λ$ with the normal state electron density we conclude that $m^{\ast}$ of the superconductivity carrier is 70 times larger than the mass of bare electrons.

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A. Kanigel, A. Keren, L. Patlagan, K. B. Chashka, B. Fisher, P. King, A. Amato. 2003-11-25. Muon Spin Relaxation Measurements in Na_xCoO_2*yH_2O. https://doi.org/10.1103/physrevlett.92.257007

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