Regensburg 2002 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 4: Supraleitung: Massivmaterialien, Bandleiter, Pinning, Vortexdynamik, Transporteigenschaften, Korngrenzen

TT 4.11: Vortrag

Montag, 11. März 2002, 17:00–17:15, H18

Non-Universal Quasi-Long Range Order in the Glassy Phase of Impure Superconductors — •Simon Bogner, Thorsten Emig, and Thomas Nattermann — Institut für Theoretische Physik, Universität zu Köln

The structural correlation functions of a weakly disordered Abrikosov lattice are calculated for the first time in a systematic RG-expansion in d=4−є dimensions [1,2]. It is shown, that in the asymptotic limit the Abrikosov lattice exhibits still quasi long range translational order described by a non-universal exponent η _G which depends on the ratio of the renormalized elastic constants κ =c₆₆/c₁₁ of the flux line (FL) lattice. Our calculations show clearly three distinct scaling regimes corresponding to the Larkin, the manifold and the asymptotic Bragg glass regime. On a wide range of intermediate length scales the FL displacement correlation function increases as a power law with twice of the manifold roughness exponent ζ_rm(κ) , which is also Our results, in particular the κ-dependence of the exponents, are in variance with those of the variational treatment with replica symmetry breaking which allows in principle an experimental discrimination between the two approaches [3].

[1] T. Emig, S. Bogner and T. Nattermann, PRL 83, 400 (1999)
S. Bogner, T. Emig and T. Nattermann, PRB 63, 174501 (2001)
T. Klein et al., Nature 413, 404 (2001)