Effective Potential and Thermodynamics for a Coupled Two-Field Bose Gas Model

We study the thermodynamics of a two-species homogeneous and dilute Bose gas that are self-interacting and quadratically coupled to each other. We make use of field-theoretical functional integral techniques and evaluate the one-loop finite-temperature effective potential for this system considering the resummation of the leading-order temperature-dependent as well as infrared contributions. The symmetry breaking pattern associated with the model is then studied by considering different values of self-species and interspecies couplings. We pay special attention to the eventual appearance of reentrant phases and/or shifts in the observed critical temperatures as compared to the monoatomic (one-field Bose) case.