Canonical spin wave theory of itinerant Kondo lattice magnets in the strong coupling regime

In this talk we present a systematic formalism to describe spin wave excitations in itinerant lattice magnets. In these systems, local magnetic moments are coupled to itinerant charge degrees of freedom and are well described by Kondo lattice models. Working in the limit of strong Kondo coupling, we perform a canonical Schrieffer-Wolff transformation and project out the high-energy fermions, resulting in a Hamiltonian of effectively spinless fermions coupled to bosonic spin wave excitations. Our canonical spin wave theory does not make assumptions regarding the ordered ground state and by design applies to all types of classical spin configurations. To that end, we include an antiferromagnetic Heisenberg exchange coupling which competes with the ferromagnetic Kondo coupling and can give rise to noncollinear and noncoplanar magnetic ground states. To demonstrate the utility of this transformation, we discuss applications on the triangular lattice and generalizations which include the addition of spin-orbit coupling, and adding a pairing term to describe the coexistence of magnetism and superconductivity.