Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
1 PublicationMagnetic-field dependence of the T*-anomaly in quasi-2D organic superconductors
Brandenburg, J.; Müller, J.; Das, P.; Lang, M.; Weickert, F.; Bartkowiak, M.; Wosnitza, J.
Abstract
The family of quasi-2D superconductors kappa(BEDTTTF)2X are model systems for strongly correlated lowdimensional metals. Recently, the unusual normalconducting state characterized by a line of anomalies T* (in the order of 40 K) has attracted considerable attention: a pseudo-gapbehavior in analogy to the high-Tc cuprates, a crossover from an incoherent bad metal to a coherent Fermiliquid regime, and a densitywavetype phase transition have been suggested as possible scenarios. To investigate the possibility of a magnetic origin we carried out detailed transport measurements in pulsed magnetic fields up to 60 T. For two different compounds, X = Cu[N(CN)2 ]Br and Cu(NCS)2 , we observed a maximum in the relative magnetoresistance change right around T* . This indicates the significance of magnetic degrees of freedom which are coupled to the transport properties. Also, for the first time we were able to determine the magneticfield dependence of T* showing a small negative shift with increasing field. We discuss the implications of our experimental data for possible models explaining the anomalous normalconducting state.
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Poster
RHMF 09 (Research on High Magnetic Fields 2009), 22.-25.07.2009, Dresden, Deutschland
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