Critical dynamics of a superconducting HgBa2CaCu2O6+δ

The in-plane longitudinal resistivity rho (xx)(T, K) of HgBa2CaCu2O6+delta (Hg-1212) film has been measured as a function of magnetic field H (0 less than or equal to H less than or equal to 9 T) and temperature T near T-c. The extracted fluctuation conductivity exhibits a dynamic scaling over a wide range of T and H, consistent with three-dimensional XY model; the static critical exponent nu is 1.1 +/- 0.1 and dynamic critical exponent z = 1.6 +/- 0.1. Hg-1212 has a larger value nu than YBCO (nu = 0.669), indicating that weaker interlayer coupling increases the value of nu. However, the value of z (= 1.6 +/- 0.1) is close to the value 1.5 of YBCO, apparently consistent with the dynamic universality class of superfluid He-4.