Al27 NMR study of the magnetic Weyl semimetal CeAlGe

Motivated by the recent observations of electronic correlation effect M. Corasaniti et al. [Phys. Rev. B 104, L121112 (2021).] and topology-stabilized magnetic fluctuations N. C. drucker et al. [Nat. Commun. 14, 5182 (2023).] in the noncentrosymmetric magnetic Weyl semimetal candidate CeAlGe, we performed systematic studies on the local static and dynamic spin susceptibilities by ²⁷Al nuclear magnetic resonance. Due to the large spin susceptibility from Ce-$4f$ electrons, the theoretically predicted responses from Weyl fermions are overwhelmed. A Knight-shift anomaly is observed below T*~50 K, a signature of the onset of coherent Kondo coupling. In addition, an anomalous peak is found in 1/T₁T near 15 K, well above the magnetic ordering temperature TN≈5 K, which is probably a consequence of topology-stabilized magnetic fluctuations. These results highlight the interplay among electronic correlation, magnetism, and band topology in this family of Kondo Weyl semimetals.