Universal critical behavior in single crystals and films of YBa${}_2$Cu${}_3$O${}_{7-\delta }$

Hua Xu, Su Li, M. C. Sullivan +4

We have studied the normal-to-superconducting phase transition in optimally-doped YBa${}_2$Cu${}_3$O${}_{7-\delta }$ in zero external magnetic field using a variety of different samples and te…