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arXiv · 2311.11617

Kondo screening in a Majorana metal

S. Lee·Y. S. Choi·S. -H. Do·W. Lee·C. H. Lee·M. Lee·M. Vojta·C. N. Wang·H. Luetkens·Z. Guguchia·K. -Y. Choi
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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 {\alpha}-RuCl3 with dilute Cr3+ (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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S. Lee, Y. S. Choi, S. -H. Do, W. Lee, C. H. Lee, M. Lee, M. Vojta, C. N. Wang, H. Luetkens, Z. Guguchia, K. -Y. Choi. 2023-11-20. Kondo screening in a Majorana metal. https://arxiv.org/abs/2311.11617

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