title: Evidence for the coexistence of an anisotropic superconducting gap and nonlocal effects in the nonmagnetic superconductor LuNi2B2C.
abstract: A study of the dependence of the heat capacity C(p)(alpha) on the field angle in LuNi2B2C reveals an anomalous disorder effect. For pure samples, C(p)(alpha) exhibits a fourfold variation as the field H<H(c2) is rotated in the [001] plane, with minima along <100> (alpha=0). A slightly disordered sample, however, develops anomalous secondary minima along <110> for mu(0)H>1 T, leading to an eightfold pattern at 2 K and 1.5 T. The anomalous pattern is discussed in terms of coexisting superconducting gap anisotropy and nonlocal effects.
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Tuson
authors.initials: T
authors.lastname: Park
authors.forename: Elbert E M
authors.initials: EE
authors.lastname: Chia
authors.forename: M B
authors.initials: MB
authors.lastname: Salamon
authors.forename: E D
authors.initials: ED
authors.lastname: Bauer
authors.forename: I
authors.initials: I
authors.lastname: Vekhter
authors.forename: J D
authors.initials: JD
authors.lastname: Thompson
authors.forename: Eun Mi
authors.initials: EM
authors.lastname: Choi
authors.forename: Heon Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Sung-Ik
authors.initials: SI
authors.lastname: Lee
authors.forename: P C
authors.initials: PC
authors.lastname: Canfield