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arXiv · 2206.06893

Possible Coexistence of Antiferromagnetic and Ferromagnetic Spin Fluctuations in the Spin-triplet Superconductor UTe2 Revealed by 125Te NMR under Pressure

Devi V. Ambika·Qing-Ping Ding·Khusboo Rana·Corey E. Frank·Elizabeth L. Green·Sheng Ran·Nicholas P. Butch·Yuji Furukawa
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Abstract

A spin-triplet superconducting state mediated by ferromagnetic (FM) spin fluctuations has been suggested to occur in the newly discovered heavy-fermion superconductor UTe$_2$. However, the recent neutron scattering measurements revealed the presence of antiferromagnetic (AFM) spin fluctuations in UTe$_2$. Here, we report the $^{125}$Te nuclear magnetic resonance (NMR) studies of a single-crystal UTe$_2$, suggesting the coexistence of FM and AFM spin fluctuations in UTe$_2$. Owing to the two different Te sites in the compound, we conclude that the FM spin fluctuations are dominant within ladders and the AFM spin fluctuations originate from the inter-ladder magnetic coupling. Although AFM spin fluctuations exist in the system, the FM spin fluctuations in the ladders may play an important role in the appearance of the spin-triplet superconducting state of UTe$_2$.

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Devi V. Ambika, Qing-Ping Ding, Khusboo Rana, Corey E. Frank, Elizabeth L. Green, Sheng Ran, Nicholas P. Butch, Yuji Furukawa. 2022-06-14. Possible Coexistence of Antiferromagnetic and Ferromagnetic Spin Fluctuations in the Spin-triplet Superconductor UTe2 Revealed by 125Te NMR under Pressure. https://doi.org/10.1103/physrevb.105.l220403

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