Confinement of Interchain Hopping by Umklapp Scattering in Two-Coupled   Chains
  The effect of umklapp scattering on interchain hopping has been investigated for two-coupled chains of interacting electrons with half-filled band. By analyzing in terms of renormalization group method, we have found that interchain hopping is renormalized to zero and is confined when a gap induced by umklapp scattering becomes larger than a critical value. From a phase diagram calculated on a plane of the interchain hopping and the gap, we discuss a role of the correlation gap which has been studied in metallic state at temperatures above spin density wave state in organic conductors. 
Y. Suzumura, M. Tsuchiizu and G. Gruner