Interface Tensions and Perfect Wetting in the Two-Dimensional Seven-State Potts Model

We present a numerical determination of the order-disorder interface tension, \sod, for the two-dimensional seven-state Potts model. We find $\sod=0.0114\pm0.0012$, in good agreement with expectations based on the conjecture of perfect wetting. We take into account systematic effects on the technique of our choice: the histogram method. Our measurements are performed on rectangular lattices, so that the histograms contain identifiable plateaus. The lattice sizes are chosen to be large compared to the physical correlation length. Capillary wave corrections are applied to our measurements on finite systems.