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Glass-like low frequency ac response of ZrB$_{12}$ and Nb single crystals in the surface superconducting state

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 نشر من قبل Menachem Tsindlekht
 تاريخ النشر 2005
  مجال البحث فيزياء
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We report experimental studies of the low frequency electrodynamics of ZrB$_{12}$ and Nb single crystals. AC susceptibility at frequencies 3 - 1000 Hz have been measured under a dc magnetic field, $H_0$, applied parallel to the sample surface. In the surface superconducting state, for several $H_0$, the real part of the ac magnetic susceptibility exhibits a logarithmic frequency dependence as for spin-glass systems. Kramers-Kronig analysis of the experimental data, shows large losses at ultra low frequencies ($<3$ Hz). The wave function slope at the surface was found. The linear response of the order parameter to the ac excitation was extracted from the experimental data.



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