Symmetry-protected non-Fermi liquids, kagome spin liquids, and the chiral Kondo lattice model

The theoretical description of non-Fermi liquids is among the most challenging questions in strongly correlated quantum matter. While there are many experimental candidates for such phases, few examples can be studied using controlled theoretical approaches. Here, we introduce a conceptual perspective to analytically describe the non-Fermi liquid physics of gapless spin liquids arising in a family of two- and three-dimensional kagome models. We first discuss a symmetry-protection mechanism that is responsible for the stability of the gapless phase. We then recast the two-dimensional kagome spin model as a chiral Kondo lattice model that can be tackled analytically using what is in a sense a generalization of coupled-wire constructions. We provide extensive numerical evidence for a gapless spin liquid in the two-dimensional kagome model and discuss generalizations to three dimensions.