ar X iv : c on d - m at / 9 40 50 24 v 1 9 M ay 1 99 4 One - Dimensional Kondo Lattice at Half Filling : Charge Properties
نویسنده
چکیده
The model of Kondo chain with M-fold degenerate band of conduction electrons of spin 1/2 at half filling interacting with localized spins S is studied. It is shown that due to the instanton effects the spin sector reveals itself in optical conductivity. Namely, the density of the charge current at large wave vector k ≈ π is proportional to the density of topological charge of the staggered magnetization. As a consequence, the optical conductivity at k = π would either have a gap equal to three spin gaps (for |M −2S| =(even) when the spin spectrum is gapful), or show a psedogap σ(ω, k = π) ∼ ω 2 for |M − 2S| = (odd). In this letter I continue to study the model of one dimensional of Kondo chain at half filling introduced in the previous publication 1. This model has the following Hamiltonian: H = r M α=1 [− 1 2 (c The conduction electrons have spin 1/2 and their band has an additional M-fold degeneracy. The value of local spins is S. It was shown in Ref. 1 that the low energy behavior of the Kondo chain with a half filled electron band is determined by antiferromagnetic correlations (the 1
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