Evidence for the coexistence of an anisotropic superconducting gap and nonlocal effects in the nonmagnetic superconductor LuNi2B2C.
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.
Park
Tuson
T
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Chia
Elbert E M
EE
Salamon
M B
MB
Bauer
E D
ED
Vekhter
I
I
Thompson
J D
JD
Choi
Eun Mi
EM
Kim
Heon Jung
HJ
Lee
Sung-Ik
SI
Canfield
P C
PC