Huge upper critical field in the superconductor with non-centrosymmetric crystal structure CeCoGe![$$_3$$](/search/images/ERPTGJA.gif)
反転中心を持たない結晶構造を持つCeCoGe
の超伝導状態における巨大上部臨界磁場
M
asson, M.-A.*; 村中 大志*; 松田 達磨; 河井 友也*; 芳賀 芳範
; Knebel, G.*; 青木 大*; Lapertot, G.*; 本多 史憲*; 摂待 力生*; Brison, J. P.*; Flouquet, J.*; 清水 克哉*; 大貫 惇睦*
M
asson, M.-A.*; Muranaka, Hiroshi*; Matsuda, Tatsuma; Kawai, Tomoya*; Haga, Yoshinori; Knebel, G.*; Aoki, Dai*; Lapertot, G.*; Honda, Fuminori*; Settai, Rikio*; Brison, J. P.*; Flouquet, J.*; Shimizu, Katsuya*; Onuki, Yoshichika*
We report the upper critical field,
, of the non-centrosymmetric compound CeCoGe
by resistivity measurements under high pressure of 7.1 GPa, for
along
and
axis, and for a magnetic field up to 17T.
is very anisotropic, saturating at low temperature for
along the
axis and linear for
along the
axis. Very high
(
) is observed for
along the
axis, with a huge value of the slope d![$$H$$](/search/images/ERECI.gif)
/d
=-47
1.3 T/K, the highest ever reported if normalized to the superconducting temperature of 0.65 K. This is most probably related to a conjunction of a heavy fermionic state and the absence of the Pauli limitation. A fit of
(
) shows that the curves for a and
axis can be reproduced with a moderate coupling Eliashberg theory.