A microscopic Kondo lattice model for the heavy fermion antiferromagnet CeIn₃

Electrons at the border of localization generate exotic states of matter across all classes of strongly correlated electron materials. Heavy electron metals are a model example, in which magnetic interactions arise from the opposing limits of localized and itinerant electrons. This remarkable duality is intimately related to the emergence of a plethora of novel quantum matter states, such as unconventional superconductivity, electronic-nematic, hidden order and most recently topological states, including skyrmion crystals, topological Kondo insulators and putative chiral superconductors. The outstanding challenge is that the archetypal Kondo lattice model that captures the underlying electronic dichotomy is notoriously difficult to solve for real materials. Using the prototypical strongly correlated antiferromagnet CeIn₃, we will show that a multi-orbital periodic Anderson model embedded with input from ab initio band structure calculations can be reduced to a simple Kondo-Heisenberg model, which captures the magnetic interactions quantitatively. This tractable Hamiltonian is validated via high-resolution neutron spectroscopy that reproduces accurately the full magnon dispersion of CeIn3.