A finite-temperature Landau theory for multilayered cuprate superconductors

A finite-temperature Landau theory is proposed to describe competing orders and interlayer tunneling in multilayered cuprate superconductors. For mono- and do uble-layered superconductors, the zero temperature order parameters and transiti on temperatures are calculated as functions of doping concentration. By comparin g such phase diagrams with relevant experiments, the phenomenolgical parameters in the theory are determined. Then we apply the theory to multilayered supercond uctors and determine the superconducting transition temperature as a function of layer number N in the underdoped, nearly optimally doped and overdoped region, respectively. In a reasonable parameter space the result of optimally doped regi on turns out to be in agreement with experiment, and as theoretical predictions, in the very underdoped and very overdoped case, Tc increases monoton ically with N.