Unconventional superconductivity in Na$_{0.35}$CoO$_{2}\cdot$1.3D$_{2}$O and proximity to a magnetically ordered phase

Y. J. Uemura; P. L. Russo; A. T. Savici; C. R. Wiebe; G. J. MacDougall; G. M. Luke; M. Mochizuki; Y. Yanase; M. Ogata; M. L. Foo; R. J. Cava

arXiv · cond-mat/0403031

Unconventional superconductivity in Na$_{0.35}$CoO$_{2}\cdot$1.3D$_{2}$O and proximity to a magnetically ordered phase

Y. J. Uemura·P. L. Russo·A. T. Savici·C. R. Wiebe·G. J. MacDougall·G. M. Luke·M. Mochizuki·Y. Yanase·M. Ogata·M. L. Foo·R. J. Cava

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Abstract

Muon spin relaxation ($μ$SR) measurements on the new layered cobalt oxide superconductor Na$_{0.35}$CoO$_{2}\cdot$1.3H$_{2}$O and its parent, non-superconducting compounds, have revealed unconventional nature of superconductivity through: (1) a small superfluid energy which implies a surprisingly high effective mass of the charge carriers, approximately 100 times the bare electron mass; (2) the superconducting transition temperature $T_{c}$ scaling with the superfluid energy following the correlations found in high-$T_{c}$ cuprate and some other two-dimensional superconductors; (3) an anisotropic pairing without broken time-reversal symmetry; and (4) the proximity of a magnetically ordered insulating phase at Na$_{0.5}$CoO$_{2}$ below $T_{N}$ = 53 K.

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Y. J. Uemura, P. L. Russo, A. T. Savici, C. R. Wiebe, G. J. MacDougall, G. M. Luke, M. Mochizuki, Y. Yanase, M. Ogata, M. L. Foo, R. J. Cava. 2004-03-01. Unconventional superconductivity in Na$_{0.35}$CoO$_{2}\cdot$1.3D$_{2}$O and proximity to a magnetically ordered phase. https://arxiv.org/abs/cond-mat/0403031

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