Müller J, Brandenburg J, Schlueter JA. Magnetic-field induced crossover of superconducting percolation regimes in the layered organic Mott system kappa-(BEDT-TTF)2Cu[N(CN) 2]Cl.
PHYSICAL REVIEW LETTERS 2009;
102:047004. [PMID:
19257466 DOI:
10.1103/physrevlett.102.047004]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Indexed: 05/27/2023]
Abstract
Fluctuation spectroscopy is used to investigate the organic bandwidth-controlled Mott system kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Cl. We find evidence for percolative-type superconductivity in the spatially inhomogeneous coexistence region of antiferromagnetic insulating and superconducting states. When the superconducting transition is driven by a magnetic field, percolation seems to be dominated by instable superconducting clusters upon approaching T(c)(B) from above, before a "classical" type of percolation is resumed at low fields, dominated by the fractional change of superconducting clusters. The 1/f noise is resolved into Lorentzian spectra in the crossover region, where the action of an individual fluctuator is enhanced, pointing to a mesoscopic phase separation.
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