ONE-PARTICLE INTERCHAIN HOPPING IN COUPLED HUBBARD CHAINS

Interchain hopping in systems of coupled chains of correlated electron s is investigated by exact diagonalization and quantum Monte Carlo met hods. For two weakly coupled Hubbard chains at commensurate densities (e.g., n=1/3), the spitting at the Fermi level between bonding and ant ibonding bands is strongly reduced (but not suppressed) by repulsive i nteractions extending to a few lattice spacings. The magnitude of this reduction is directly connected to the exponent ct of the one-dimensi onal Luttinger liquid. However, we show that the incoherent part of th e single-particle spectral function is much less affected by the inter chain coupling. This suggests that incoherent interchain hopping could occur for intermediate alpha values.