  The Kondo lattice is one of the classic examples of strongly correlated
electronic systems. We conduct a controlled study of the Kondo lattice in one
dimension, highlighting the role of excitations created by the composite
fermion operator. Using time-dependent matrix-product-state methods we compute
various correlation functions and contrast them with both large-N mean-field
theory and the strong-coupling expansion. We show that the composite fermion
operator creates long-lived, charge-e and spin-1/2 excitations, which cover the
low-lying single-particle excitation spectrum of the system. Furthermore, spin
excitations can be thought to be composed of such fractionalized
quasi-particles with a residual interaction which tend to disappear at weak
Kondo coupling.
