Slow dynamics of electrons in the paramagnetic state of UTe

UTeの常磁性相における電子系の遅い揺らぎ

徳永 陽  ; 酒井 宏典   ; 神戸 振作  ; 芳賀 芳範   ; 常盤 欣文  ; Opletal, P.  ; 藤林 裕己*; 金城 克樹*; 北川 俊作*; 石田 憲二*; 仲村 愛*; 清水 悠晴*; 本間 佳哉*; Li, D.*; 本多 史憲*; 青木 大*

Tokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Haga, Yoshinori; Tokiwa, Yoshifumi; Opletal, P.; Fujibayashi, Hiroki*; Kinjo, Katsuki*; Kitagawa, Shunsaku*; Ishida, Kenji*; Nakamura, Ai*; Shimizu, Yusei*; Homma, Yoshiya*; Li, D.*; Honda, Fuminori*; Aoki, Dai*

UTe is a novel uranium-based superconductor with a rather high transition temperature of K. The compound attracted particular attention, because of the strong possibility of the spin-triplet Cooper pairing, which is a natural candidate for topological superconductivity in a bulk material. In this study, we performed Te-NMR experiments on a Te enriched single crystal of UTe. The field and temperature dependences of the spin-spin relaxation rate of in field applied along the -axis revealed slow electronic dynamics developing in the paramagnetic state. The observed slow fluctuations are concerned with a successive growth of long-range electronic correlations below 3040 K. We suggest that UTe would be located on the paramagnetic side near an electronic phase boundary, where either the magnetic or Fermi-surface instability would be the origin of the characteristic fluctuations.