On the Ginzburg-Landau Free Energy of Charge Density Waves with a Three-Dimensional Order

The effective free energy of a charge density wave (CDW) with a three-dimensional order is derived from a microscopic model (Fr\"olich model) based on the path integral method. Electron hoping and Coulomb interaction between chains are taken into account perturbatively, leading to an elastic interchain coupling of the CDW ordered state.