Anisotropic response of spin susceptibility in the superconducting state of UTe2 probed with 125Te−NMR measurement

To investigate spin susceptibility in a superconducting (SC) state, we measured the 125Te-nuclear magnetic resonance (NMR) Knight shifts at magnetic fields (H) up to 6.5 T along the b and c axes of single-crystal UTe2, a promising candidate for a spin-triplet superconductor. In the SC state, the Knight shifts along the b and c axes (Kb and Kc, respectively) decreased slightly and the decrease in Kb was almost constant up to 6.5 T. The reduction in Kc decreased with increasing H, and Kc was unchanged through the SC transition temperature at 5.5 T, excluding the possibility of spin-singlet pairing. Our results indicate that spin susceptibilities along the b and c axes slightly decrease in the SC state in low H, and the H response of SC spin susceptibility is anisotropic in the bc plane. We discuss the possible d-vector state within the spin-triplet scenario and suggest that the dominant d-vector component for the case of H∥b changes above 13 T, where Tc increases with increasing H.

Article information

Nakamine, G; Kinjo, K; Kitagawa, S; Ishida, K; Tokunaga, Y; Sakai, H; Kambe, S; Nakamura, A; Shimizu, Y; Homma, Y; Li, D; Honda, F; Aoki, D

Anisotropic response of spin susceptibility in the superconducting state of UTe2 probed with 125Te − NMR measurement Journal Article

In: Physical Review B, vol. 103, no. 10, pp. L100503, 2021.

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