# Universal critical behavior in single crystals and films of YBa$2$Cu$3$O${7-δ}$ - Condensed Matter > Superconductivity

Universal critical behavior in single crystals and films of YBa$2$Cu$3$O${7-δ}$ - Condensed Matter > Superconductivity - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We have studied the normal-to-superconducting phase transition inoptimally-doped YBa$2$Cu$3$O${7-\delta}$ in zero external magnetic fieldusing a variety of different samples and techniques. Using DC transportmeasurements, we find that the dynamical critical exponent $z=1.54\pm0.14$, andthe static critical exponent $u=0.66\pm0.10$ for both films whenfinite-thickness effects are included in the data analysis and single crystalswhere finite-thickness effects are unimportant. We also measured thin filmsat different microwave frequencies and at different powers, which allowed us tosystematically probe different length scales to avoid finite-thickness effects.DC transport measurements were also performed on the films used in themicrowave experiments to provide a further consistency check. These microwaveand DC measurements yielded a value of z consistent with the other results,$z=1.55\pm0.15$. The neglect of finite-thickness, finite-current, andfinite-frequency effects may account for the wide ranges of values for $u$and $z$ previously reported in the literature.

Autor: Hua Xu, Su Li, M. C. Sullivan, Kouji Segawa, Steven M. Anlage, Yoichi Ando, C. J. Lobb

Fuente: https://arxiv.org/