Critical dynamics of superconducting BSCCO films

TL;DR

This study investigates the critical fluctuations in the complex conductivity of BSCCO superconducting films near their transition temperature, revealing a consistent dynamic critical exponent of 2.0 and confirming 3D-XY universality class behavior.

Contribution

It provides the first detailed measurement of the dynamic critical exponent in BSCCO films using a two-coil inductive technique, highlighting non-linear effects near the critical temperature.

Findings

Static 3D-XY critical exponent observed

Dynamic critical exponent z = 2.0 determined

Non-linear effects are significant near T_c

Abstract

We report on a systematic investigation of the critical fluctuations in the complex conductivity of epitaxially-grown Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ films for ${T \lesssim T_c}$ using a two-coil inductive technique at zero applied field. We observe the static 3D-XY critical exponent in the superfluid density near $T_{c}$. Linear scaling analysis close to the critical temperature yields a dynamic critical exponent of $z = 2.0$ for small drive currents, but non-linear effects are seen to be important. At $T_{c}$, a non-linear scaling analysis also yields a 3D dynamic exponent of $z = 2.0$.