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DOE OSTI · 2222621

Kondo screening in a Majorana metal

Lee, S.·Choi, Y. S.·Do, S. -H.·Lee, W.·Lee, C. H.·Lee, Minseong·Vojta, M.·Wang, C. N.·Luetkens, H.·Guguchia, Z.·Choi, K. -Y.
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Abstract

Kondo impurities provide a nontrivial probe to unravel the character of the excitations of a quantum spin liquid. In the S = 1/2 Kitaev model on the honeycomb lattice, Kondo impurities embedded in the spin-liquid host can be screened by itinerant Majorana fermions via gauge-flux binding. Here, we report experimental signatures of metallic-like Kondo screening at intermediate temperatures in the Kitaev honeycomb material α-RuCl 3 with dilute Cr 3+ (S = 3/2) impurities. The static magnetic susceptibility, the muon Knight shift, and the muon spin-relaxation rate all feature logarithmic divergences, a hallmark of a metallic Kondo effect. Concurrently, the linear coefficient of the magnetic specific heat is large in the same temperature regime, indicating the presence of a host Majorana metal. This observation opens new avenues for exploring uncharted Kondo physics in insulating quantum magnets.

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Lee, S., Choi, Y. S., Do, S. -H., Lee, W., Lee, C. H., Lee, Minseong, Vojta, M., Wang, C. N., Luetkens, H., Guguchia, Z., Choi, K. -Y.. 2023-11-16. Kondo screening in a Majorana metal. https://doi.org/10.1038/s41467-023-43185-3

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