Extremely high upper critical magnetic field of the noncentrosymmetric heavy fermion superconductor CeRhSi3.
We report an extremely high upper critical field B(c2) in the noncentrosymmetric heavy fermion superconductor CeRhSi3 for a magnetic field B along the tetragonal c axis. B(c2)(T=0) possibly reaching 30 T is much higher than B(c2)(0)=7 T for B perpendicular c and greatly exceeds the paramagnetic limiting field. The strong anisotropy of B(c2)(0) with extremely high B(c2)(0) for B || c is qualitatively explained by the paramagnetic pair-breaking mechanism specific to the noncentrosymmetric superconductor. However, an unusual B(c2)(T) curve with a positive curvature for B || c cannot be explained satisfactorily by conventional orbital pair-breaking models.
Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan.
N
N
Kimura
K
K
Ito
H
H
Aoki
S
S
Uji
T
T
Terashima