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Register a new userNonuniversal Correlations and Crossover Effects in the Bragg-Glass Phase of Impure Superconductors
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The structural correlation functions of a weakly disordered Abrikosov lattice are calculated in a functional RG-expansion in $d=4-epsilon$ dimensions. It is shown, that in the asymptotic limit the Abrikosov lattice exhibits still quasi-long-range translational order described by a {it nonuniversal} exponent $eta_{bf G}$ which depends on the ratio of the renormalized elastic constants $kappa ={c}_{66}/ {c}_{11}$ of the flux line (FL) lattice. Our calculations clearly demonstrate three distinct scaling regimes corresponding to the Larkin, the random manifold and the asymptotic Bragg-glass regime. On a wide range of {it intermediate} length scales the FL displacement correlation function increases as a power law with twice the manifold roughness exponent $zeta_{rm RM}(kappa) $, which is also {it nonuniversal}. Correlation functions in the asymptotic regime are calculated in their full anisotropic dependencies and various order parameters are examined. Our results, in particular the $kappa$-dependency 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.
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