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 Please use this identifier to cite or link to this item: https://dspace.lboro.ac.uk/2134/1174

 Title: The "normal" state of superconducting cuprates might really be normal after all Authors: Zavaritsky, V.N.Alexandrov, A.S. Keywords: Superconductivity Issue Date: 2004 Abstract: High magnetic field studies of cuprate superconductors revealed a non-BCS temperature dependence of the upper critical field $H_{c2}(T)$ determined resistively by several groups. These determinations caused some doubts on the grounds of both the contrasting effect of the magnetic field on the in-plane and out-of-plane resistances reported for large Bi2212 sample and the large Nernst signal \emph{well above} $T_{c}$. Here we present both $\rho_{ab}(B)$ and $\rho_{c}(B)$ of tiny Bi2212 crystals in magnetic fields up to 50 Tesla. None of our measurements revealed a situation when on the field increase $\rho_c$ reaches its maximum while $\rho_{ab}$ remains very small if not zero. The resistive %upper critical fields estimated from the in-plane and out-of-plane $H_{c2}(T)$ estimated from $\rho_{ab}(B)$ and $\rho_{c}(B)$ are approximately the same. Our results support any theory of cuprates that describes the state above the resistive phase transition as perfectly normal with a zero off-diagonal order parameter. In particular, the anomalous Nernst effect above the resistive phase transition in high-$T_{c}$ cuprates can be described quantitatively as a normal state phenomenon in a model with itinerant and localised fermions and/or charged bosons. Description: This is a pre-print. It is also available at: http://arxiv.org/abs/cond-mat/0410075. URI: https://dspace.lboro.ac.uk/2134/1174 Appears in Collections: Pre-Prints (Physics)

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