Te-NMR study of magnetic fluctuations in a newly discovered uranium-based superconductor UTe

Tokunaga, Yo  ; Sakai, Hironori   ; Kambe, Shinsaku  ; Hattori, Taisuke; Higa, Nonoka*; Nakamine, Genki*; Kitagawa, Shunsaku*; Ishida, Kenji*; Nakamura, Ai*; Shimizu, Yusei*; Li, D. X.*; Homma, Yoshiya*; Honda, Fuminori*; Aoki, Dai*

Te NMR studies have been performed on a newly discovered heavy fermion superconductor UTe.Using a single crystal, we have measured the Te NMR Knight shift and spin-lattice relaxation rate for fields along the three orthorhombic crystal axes. The data confirm a moderate Ising anisotropy for both the static () and dynamical susceptibilities () in the paramagnetic state above about 20 K. Around 20 K, however, we have observed a sudden loss of NMR spin-echo signal due to sudden enhancement of the NMR spin-spin relaxation rate , when the field is applied along the easy axis of magnetization (= axis).