title: Temperature dependence of the penetration depth in Sr2RuO4: evidence for nodes in the gap function
abstract: We report measurements of the magnetic penetration depth in single crystals of Sr2RuO4 down to 0.04 K using a tunnel-diode based, self-inductive technique. We observe a power law temperature dependence below 0.8 K, with no sign of a second phase transition nor of a crossover predicted for a multiband superconductor. A power law dependence suggests that the gap function has nodes, inconsistent with candidate p-wave states. We argue that nonlocal effects, rather than impurity scattering, can explain the observed T2 dependence instead of the T-linear behavior expected for line nodes.
authors.affiliation: Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, Illinois 61801, USA.
authors.initials: I
authors.lastname: Bonalde
authors.initials: BD
authors.lastname: Yanoff
authors.initials: MB
authors.lastname: Salamon
authors.lastname: Van Harlingen DJ
authors.initials: EM
authors.lastname: Chia
authors.initials: ZQ
authors.lastname: Mao
authors.initials: Y
authors.lastname: Maeno