Magnetic interactions in heavy-fermion metals arise from the two opposing limits of localized and itinerant electrons. This duality is responsible for numerous novel quantum-matter states, such as unconventional superconductivity, electronic nematicity, or skyrmion-lattice order in centrosymmetric crystals. The Kondo-lattice model, which captures the underlying physics of f-electrons, is notoriously difficult to solve for real materials and was therefore never solved quantitatively. CeIn3 is a prototypical example having a relatively simple crystal structure and showing quantum critical behavior as well as unconventional superconductivity on pressure tuning. At ambient conditions and temperatures below 10 K, CeIn3 establishes antiferromagnetic long-range order. In the study that I will present, we show that a multi-orbital periodic Anderson model together with ab-initio bandstructure calculations can be reduced to a modified Kondo-Heisenberg model that captures all relevant magnetic interactions and that further establishes the antiferromagnetic ground state. Notably, as a key signature the model suggests the emergence of magnons that have extremely high velocities. We used high-resolution neutron spectroscopy to probe the low-energetic magnetic excitations and found astounding agreement with the theoretical prediction. The same soft modes may be the key for the emergence of superconductivity and may further guide us to a better understanding not only of unconventional superconductivity, but also of exotic quantum states across all classes of strongly correlated electron materials.
See also Ref. [1]
[1] W. Simeth, Z. Wang, E. A. Ghioldi, D. M. Fobes, A. Podlesnyak, N. H. Sung, E. D. Bauer, J. Lass, J. Vonka, D. G. Mazzone, C. Niedermayer, Y. Nomura, R. Arita, C. D. Batista, F. Ronning, and M. Janoschek, arXiv:2208.02211.
Dr. Jitae Park
Dr. Theresia Heiden-Hecht
Dr. Apostolos Vagias