Quantum phase diagram for homogeneous Bose‐Einstein condensate

  title={Quantum phase diagram for homogeneous Bose‐Einstein condensate},
  author={Hagen Kleinert and Sebastian Schmidt and Axel Pelster},
  journal={Annalen der Physik},
We calculate the quantum phase transition for a homogeneous Bose gas in the plane of s‐wave scattering length as and temperature T. This is done by improving a one‐loop result near the interaction‐free Bose‐Einstein critical temperature Tc(0) with the help of recent high‐loop results on the shift of the critical temperature due to a weak atomic repulsion based on variational perturbation theory. The quantum phase diagram shows a nose above Tc(0), so that we predict the existence of a reentrant… 
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