Non-linear current through a barrier in 1D wires with finite-range interactions

The transport properties of a tunnel barrier in a one-dimensional wire are investigated at finite voltages and temperatures. We generalize the Luttinger model to account for finite ranges of the interaction. This leads to deviations from the power law behaviour first derived by Kane and Fisher. At high energies the influence of the interaction disappears and the Coulomb blockade is suppressed. The crossover in the voltage or in the temperature dependence can provide a direct measure for the range of the interaction.