The strong coupling Kondo lattice model as a Fermi gas

Abstract

The strong coupling half-filled Kondo lattice model is an important example of a strongly interacting dense Fermi system for which conventional Fermi gas analysis has thus far failed. We remedy this by deriving an exact transformation that maps the model to a dilute gas of weakly interacting electron and hole quasiparticles that can then be analyzed by conventional dilute Fermi gas methods. The quasiparticle vacuum is a singlet Mott insulator for which the quasiparticle dynamics are simple. Since the transformation is exact, the electron spectral weight sum rules are obeyed exactly. Subtleties in understanding the behavior of electrons in the singlet Mott insulator can be reduced to a fairly complicated but precise relation between quasiparticles and bare electrons. The theory of free quasiparticles can be interpreted as an exactly solvable model for a singlet Mott insulator, providing an exact model in which to explore the strong coupling regime of a singlet Kondo insulator.

10pages, 2 figures

References in corpus (3)

• Sum Rules and Ward Identities in the Kondo Lattice
• Exact Transformation for Spin-Charge Separation of Spin-half Fermions without Constraints
• Properties of the doped spin 3/2 Mott insulator near half filling

Cited by in corpus (5)

• Faithful fermionic representations of the Kondo lattice model
• Exotic quantum statistics and thermodynamics from a number-conserving theory of Majorana fermions
• Nonlinear Bogolyubov-Valatin transformations: 2 modes
• Ferromagnetism in the one-dimensional Kondo lattice: mean-field approach via Majorana fermion canonical transformation
• Doping driven Small-to-Large Fermi surface transition and d-wave superconductivity in a two-dimenional Kondo lattice