Dynamic Scaling and Two-Dimensional High-Tc Superconductors

Abstract

There has been ongoing debate over the critical behavior of two-dimensional superconductors; in particular for high Tc superconductors. The conventional view is that a Kosterlitz-Thouless-Berezinskii transition occurs as long as finite size effects do not obscure the transition. However, there have been recent suggestions that a different transition actually occurs which incorporates aspects of both the dynamic scaling theory of Fisher, Fisher, and Huse and the Kosterlitz-Thouless-Berezinskii transition. Of general interest is that this modified transition apparently has a universal dynamic critical exponent. Some have countered that this apparent universal behavior is rooted in a newly proposed finite-size scaling theory; one that also incorporates scaling and conventional two-dimensional theory. To investigate these issues we study DC voltage versus current data of a 12 angstrom thick YBCO film. We find that the newly proposed scaling theories have intrinsic flexibility that is relevant to the analysis of the experiments. In particular, the data scale according to the modified transition for arbitrarily defined critical temperatures between 0 K and 19.5 K, and the temperature range of a successful scaling collapse is related directly to the sensitivity of the measurement. This implies that the apparent universal exponent is due to the intrinsic flexibility rather than some real physical property. To address this intrinsic flexibility, we propose a criterion which would give conclusive evidence for phase transitions in two-dimensional superconductors. We conclude by reviewing results to see if our criterion is satisfied.

14 pages

References in corpus (8)

• Is there a vortex-glass transition in high-temperature superconductors?
• Dynamic scaling for 2D superconductors, Josephson junction arrays and superfluids
• Dynamic critical exponent of two-, three-, and four-dimensional XY models with relaxational and resistively shunted junction dynamics
• Analysis of current-voltage characteristics of two-dimensional superconductors: finite-size scaling behavior in the vicinity of the Kosterlitz Thouless transition
• Finite-Size Effects and Dynamical Scaling in Two-Dimensional Josephson Junction Arrays
• Renormalization Group Study of the Intrinsic Finite Size Effect in 2D Superconductors
• Ubiquitous finite-size scaling features in IV characteristics of various dynamic XY models in two dimensions
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Cited by in corpus (14)

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• Interaction of vortices in thin superconducting films and Berezinskii-Kosterlitz-Thouless transition
• Critical microwave-conductivity fluctuations across the phase diagram of superconducting La${}_{2-x}$Sr${}_x$CuO${}_4$ thin films
• Phase slips in superconducting films with constrictions
• Size effects in the nonlinear resistance and flux creep in a virtual Berezinskii-Kosterlitz-Thouless state of superconducting films
• Superconducting transition of a two-dimensional Josephson junction array in weak magnetic fields
• Scaling, Finite Size Effects, and Crossovers of the Resistivity and Current-Voltage Characteristics in Two-Dimensional Superconductors
• Anisotropic Kosterlitz-Thouless Transition Induced by Hard-Wall Boundaries
• A tool to estimate the critical dynamics and thickness of superconducting films and interfaces
• High-Tc Superconductivity in Ultra-thin Crystals: Implications for Microscopic Theory
• Transport properties of clean and disordered Josephson junction arrays
• Effect of Disorder on the Superfluid Transition in Two-Dimensional Systems
• The BKT Transition and its Dynamics in a Spin Fluid
• Scaling determination of the nonlinear I-V characteristics for 2D superconducting networks