title: Critical points in heavy ion irradiated untwinned YBa(2)Cu3O(7-delta) crystals
abstract: The critical points in untwinned YBa(2)Cu(3)O(7-delta) crystals with dilute columnar defects are investigated. We find a convergence of a first order vortex melting line with an irreversibility line associated with the onset of the Bose glass critical regime at the lower critical point. In addition, we find that columnar defects raise the upper critical point, implying that vortex line meandering is a basic feature controlling its position.
authors.affiliation: Materials Science Division and Science and Technology Center for Superconductivity, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.initials: WK
authors.lastname: Kwok
authors.initials: RJ
authors.lastname: Olsson
authors.initials: G
authors.lastname: Karapetrov
authors.initials: LM
authors.lastname: Paulius
authors.initials: WG
authors.lastname: Moulton
authors.initials: DJ
authors.lastname: Hofman
authors.initials: GW
authors.lastname: Crabtree