Abstract
Fluctuation spectroscopy is used to investigate the organic bandwidth-controlled Mott system . 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 from above, before a “classical” type of percolation is resumed at low fields, dominated by the fractional change of superconducting clusters. The 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.
- Received 3 November 2008
DOI:https://doi.org/10.1103/PhysRevLett.102.047004
©2009 American Physical Society