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VOLUME 91 (2010) | ISSUE 11 |
PAGE 639
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Critical disorder effects in Josephson-coupled quasi-one-dimensional superconductors
E. Nakhmedov+*, R. Oppermann
+Institut für Theoretische Physik, Universität Würzburg, D-97074 Würzburg, Germany *Institute of Physics, Azerbaijan National Academy of Sciences,H. Cavid str. 33, AZ1143 Baku, Azerbaijan Institut de Physique Théorique, CEA Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette, France
Abstract
Effects of non-magnetic randomness on the critical temperature
Tc and diamagnetism are studied in a class of quasi-one
dimensional superconductors. The energy of Josephson-coupling
between wires is considered to be random, which is typical for
dirty organic superconductors. We show that this randomness
destroys phase coherence between the wires and Tc vanishes
discontinuously when the randomness reaches a critical value. The
parallel and transverse components of the penetration depth are
found to diverge at different critical temperatures Tc(1)
and Tc, which correspond to pair-breaking and phase-coherence
breaking. The interplay between disorder and quantum phase
fluctuations results in quantum critical behavior at T=0,
manifesting itself as a superconducting-normal metal phase
transition of first-order at a critical disorder strength.
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