Low-Temperature Series for the Square Lattice Potts Model by the Improved Finite-Lattice Method

The low-temperature series are calculated for the free energy, magnetization and susceptibility in the Q-state Potts model on the square lattice, using the improved algorithm of the finite lattice method. The series are obtained to the order of $z^{41}$ for each of Q=5-50, and the result of their Pad\'e type analysis is compared with those of the large-Q expansion and the Monte Carlo simulations.