Superconducting Order Parameter in UTe2 Determined by Knight Shift Measurement.

Authors :: Fujibayashi, Hiroki
Nakamine, Genki
Kinjo, Katsuki
Kitagawa, Shunsaku
Ishida, Kenji
Tokunaga, Yo
Sakai, Hironori
Kambe, Shinsaku
Nakamura, Ai
Shimizu, Yusei
Homma, Yoshiya
Li, Dexin
Honda, Fuminori
Aoki, Dai
Source :: Journal of the Physical Society of Japan; 4/15/2022, Vol. 91 Issue 4, p1-4, 4p
Publication Year :: 2022
Abstract: This study investigates the spin susceptibility in U-based superconductor UTe<subscript>2</subscript> in the superconducting (SC) state by using Knight shift measurements for a magnetic field H along the a axis, which is the magnetic easy axis of UTe<subscript>2</subscript>. Although a tiny anomaly ascribed to the SC diamagnetic effect was observed just below the SC transition temperature T<subscript>c</subscript>, the a-axis Knight shift in the SC state shows no significant decrease, following the extrapolation from the normal-state temperature dependence. This indicates that the spin susceptibility is nearly unchanged below T<subscript>c</subscript>. Considering the previous Knight shift results for \(H\parallel b\) and \(H\parallel c\) , the dominant SC state is determined to be B<subscript>3u</subscript> in the spin-triplet pairing, which is consistent with the spin anisotropy in the normal state. The present result shows that UTe<subscript>2</subscript> is a spin-triplet superconductor with spin degrees of freedom. [ABSTRACT FROM AUTHOR]