Scaling, finite size effects, and crossovers of the resistivity and current-voltage characteristics in two-dimensional superconductors
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 87, no 22, 224506- p.Article in journal (Refereed) Published
We revisit the scaling properties of the resistivity and the current-voltage characteristics at and below the Berezinskii-Kosterlitz-Thouless transition, both in zero and nonzero magnetic fields. The scaling properties are derived by integrating the renormalization group flow equations up to a scale where they can be reliably matched to simple analytic expressions. The vortex fugacity turns out to be dangerously irrelevant for these quantities below T-c, thereby altering the scaling behavior. We derive the possible crossover effects as the current, magnetic field, or system size is varied, and find a strong multiplicative logarithmic correction near T-c, all of which is necessary to account for when interpreting experiments and simulation data. Our analysis clarifies a longstanding discrepancy between the finite size dependence found in many simulations and the current-voltage characteristics of experiments. We further show that the logarithmic correction can be avoided by approaching the transition in a magnetic field, thereby simplifying the scaling analysis. We confirm our results by large-scale numerical simulations, and calculate the dynamic critical exponent z, for relaxational Langevin dynamics and for resistively and capacitively shunted Josephson junction dynamics.
Place, publisher, year, edition, pages
American Physical Society , 2013. Vol. 87, no 22, 224506- p.
Josephson-Junction Arrays, Iv Characteristics, Phase-Transitions, Coulomb Gas, Xy Models, Dynamics, Films, Exponent
IdentifiersURN: urn:nbn:se:kth:diva-124725DOI: 10.1103/PhysRevB.87.224506ISI: 000320604800004ScopusID: 2-s2.0-84879710351OAI: oai:DiVA.org:kth-124725DiVA: diva2:638354
FunderSwedish Research Council, 621-2007-5138
QC 201307302013-07-302013-07-292013-07-30Bibliographically approved