Hole doping and disorder effects on the one-dimensional Kondo lattice, for ferromagnetic Kondo couplings

Abstract

We investigate the one-dimensional Kondo lattice model (1D KLM) for ferromagnetic Kondo couplings. The so-called ferromagnetic 2-leg spin ladder and the S=1 antiferromagnet occur as new one-dimensional Kondo insulators. Both exhibit a spin gap. But, in contrast to the strong coupling limit, the Haldane state which characterizes the 2-leg spin ladder Kondo insulator cannot fight against very weak exterior perturbations. First, by using standard bosonization techniques, we prove that an antiferromagnetic ground state occurs by doping with few holes; it is characterized by a form factor of the spin-spin correlation functions which exhibits two structures respectively at $q=\pi$ and $q=2k_F$. Second, we prove precisely by using renormalization group methods that the Anderson-localization inevitably takes place in that weak-coupling Haldane system, by the introduction of quenched randomness; the spin-fixed point rather corresponds to a ``glass'' state. Finally, a weak-coupling ``analogue'' of the S=1 antiferromagnet Kondo insulator is proposed; we show that the transition into the Anderson-localization state may be avoided in that unusual weak-coupling Haldane system.

22 pages, TEX and 2 figures (long version); to be published in Phys. Rev. B (December 97)

References in corpus (5)

• Surprises on the Way from 1D to 2D Quantum Magnets: the Novel Ladder Materials
• Dimerization and Incommensurate Spiral Spin Correlations in the Zigzag Spin Chain: Analogies to the Kondo Lattice
• Antiferromagnetic spin ladders: crossover between spin S = 1/2 and S = 1 chains
• Random Bonds and Topological Stability in Gapped Quantum Spin Chains
• Exact Results for 1D Kondo Lattice from Bosonization

Cited by in corpus (3)

• The one dimensional Kondo lattice model at partial band filling
• Spin and lattice effects in the Kondo lattice model
• Heavy electrons from Hund's rule and short-range Antiferromagnetism