Vortex Glass Scaling of Conductivity
1997; Physical Society of Japan; Volume: 66; Issue: 6 Linguagem: Inglês
10.1143/jpsj.66.1603
ISSN1347-4073
Autores Tópico(s)Quantum and electron transport phenomena
ResumoThe scaling behavior of dc conductivity σ x x in a current perpendicular to the magnetic field near a vortex-glass (VG) transition is addressed in terms of the Ginzburg-Landau (GL) model and Kubo formula and by assuming a universal scaling behavior of the VG correlation function. Together with the uncorrelated T c -disorder, we also take account of another type of uncorrelated disorder which becomes a familiar expression once assuming the phase-only approximation. Based on a calculation perturbative in the pinning disorders, we show that both of these uncorrelated disorders are necessary in order to obtain the universal scaling of σ x x proposed by Fisher et al . [Phys. Rev. B 43 (1991) 130], and that, if either of them is negligible, the scaling behavior of σ x x can be apparently nonuniversal even deep in the VG critical region. Our results explain, without invoking a possible destruction of true VG transition due to screening, why the vanishing resistivity data show a nonuniversal behavior with a field-dependent exponent in situations with point disorder suppressing the first-order transition.
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