Spin-charge separation, anomalous scaling, and the coherence of hopping in exactly solved two-chain models

The coherence of transport between two one-dimensional interacting Fermi liquids, coupled by single-particle hopping and interchain interaction, is examined in the context of two exactly soluble models. It is found that the coherence of the interchain hopping depends on the interplay between interchain hopping and interchain interaction terms, and not simply on the ground state spectral properties of an isolated chain. Specifically, the splitting of levels associated with interchain hopping in a g₄ soluble model is found to be enhanced by the introduction of interchain interaction. It is also shown that, for an exactly solvable model with both g₂ and g₄ interactions, coherent interchain hopping coexists with anomalous scaling and non-Fermi liquid behavior in the chain direction.