Intra- and inter-chain dynamic response functions in quasi-one-dimensional conductors

Intra- and inter-chain excitation spectra are studied in a spinless fermion model on a two-leg ladder at half filling. Numerical results are obtained by application of the density matrix renormalization group technique to the quantum transfer matrix for infinite systems. Near the metal-insulator transition, the intra-chain Coulomb repulsion is found to affect local current correlation more sensitively in the rung direction than in the leg direction.