Dynamic Measurement of Percolative Critical Exponents in Disordered Josephson Junction Arrays
Abstract
The complex conductance G\(ω\) of site-diluted Josephson junction arrays close to the percolation threshold was measured over a wide range of frequencies ω. Well below Tc both the superfluid [ωImG] and dissipative [ReG] components are independent of ω below a critical frequency ωc, whereas G\(ω\)~ω-u with u~12 for ω>ωc. This is shown to reflect the crossover from a Euclidean regime \(ω<ωc\) dominated by phononlike modes of the phase system to a fractal regime \(ω>ωc\), where the relevant excitations are localized fractons. Percolative critical exponents extracted from the data are consistent with theoretical predictions.
- Publication:
-
Physical Review Letters
- Pub Date:
- October 1996
- DOI:
- 10.1103/PhysRevLett.77.3905
- Bibcode:
- 1996PhRvL..77.3905E