title: Transport in ultraclean YBa2Cu3O7: neither unitary nor born impurity scattering.
abstract: The thermal conductivity of ultraclean YBa2Cu3O7 was measured at very low temperature in magnetic fields up to 13 T. The temperature and field dependence of the electronic heat conductivity show that two widespread assumptions of transport theory applied to unconventional superconductors fail for clean cuprates: impurity scattering cannot be treated in the usual unitary limit (nor indeed in the Born limit), and scattering of quasiparticles off vortices cannot be neglected. Our study also sheds light on the long-standing puzzle of a sudden onset of a "plateau" in the thermal conductivity of Bi-2212 versus field.
authors.affiliation: Department of Physics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: R W
authors.initials: RW
authors.lastname: Hill
authors.forename: Christian
authors.initials: C
authors.lastname: Lupien
authors.forename: M
authors.initials: M
authors.lastname: Sutherland
authors.forename: Etienne
authors.initials: E
authors.lastname: Boaknin
authors.forename: D G
authors.initials: DG
authors.lastname: Hawthorn
authors.forename: Cyril
authors.initials: C
authors.lastname: Proust
authors.forename: F
authors.initials: F
authors.lastname: Ronning
authors.forename: Louis
authors.initials: L
authors.lastname: Taillefer
authors.forename: Ruixing
authors.initials: R
authors.lastname: Liang
authors.forename: D A
authors.initials: DA
authors.lastname: Bonn
authors.forename: W N
authors.initials: WN
authors.lastname: Hardy