The Kosterlitz-Thouless Transition, Finite-Size Effects and Dynamical 
Scaling in Two-Dimensional  Josephson Junction Arrays and 
Superconducting Films

R. S. Newrock
Physics Department
University of Cincinnati
Cincinnati, Ohio45221-0011 USA

Scaling has been shown to be a powerful tool for understanding 
critical phenomena and phase transitions.  However it must be applied 
with considerable care.  In recent years many groups have used Fisher,
Fisher, and Huse dynamical scaling to investigate and demonstrate 
details of the superconducting phase transition.  Recently the 
application of dynamic scaling to the current-voltage isotherms of 
two-dimensional superconducting systems led one group to conclude 
that such systems may not be Kosterlitz-Thouless-Berezinskii (KTB) 
like. Their analysis showed transition temperatures significantly 
lower than that yielded by the standard analysis of such systems and 
critical exponents z of 5 or higher, much greater than the value of 2 
expected for a KTB transition.  In this paper we discuss our 
investigations of scaling using simulated IV isotherms for 
Josephson-junction arrays and our scaling analysis of high-temperature 
superconducting films. We show that when finite-size effects are 
properly accounted for these systems show the KTB transition with z=2.