content_image/334061.jpg
<img src='content_image/334061.jpg'>

uniform Bose gas, the molecular-BEC state can only exist with positive scattering lengths, a$_{s}$ > 0. In a trap, the molecular-BEC state may be stabilized by the finite-size effect, similar to trapped BEC with attractive interactions [18]. 

## E. Mean-field phase diagram 

The upper boundary of the molecular-BEC phase is determined by the disappearance of order parameter Δ = 0, corresponding to the second-order phase transition between the normal and molecular-BEC phases. At the transition temperature T$_{p}$ , Eq. (4) is the same 

