Spin-triplet superconductivity in UNi(2)Al(3) revealed by the (27)Al Knight shift measurement.
We report (27)Al Knight shift ( (27)K) measurement on a single-crystal UNi(2)Al(3) that reveals a coexistence of superconductivity and a spin-density-wave (SDW) type of magnetic ordering ( T(SDW) = 4.5 K). The spin part of (27)K, (27)K(s), does not change down to 50 mK across the superconducting (SC) transition temperature T(c) approximately 0.9 K. In contrast with the isostructural compound UPd(2)Al(3) ( T(c) approximately 2 K), which was identified to be a spin-singlet d-wave superconductor, the behavior of (27)K strongly supports that UNi(2)Al(3) , like UPt(3) and Sr(2)RuO(4), belongs to a class of spin-triplet SC pairing state superconductors.
Ishida
K
K
Department of Physical Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
Ozaki
D
D
Kamatsuka
T
T
Tou
H
H
Kyogaku
M
M
Kitaoka
Y
Y
Tateiwa
N
N
Sato
N K
NK
Aso
N
N
Geibel
C
C
Steglich
F
F