Reentrant Phenomenon in Quantum Phase Diagram of Optical Boson Lattice

Kleinert, H.; Schmidt, S.; Pelster, A.

Reentrant Phenomenon in Quantum Phase Diagram of Optical Boson Lattice

Authors

Kleinert, H.

Schmidt, S.

Pelster, A.

Description

We calculate the location of the quantum phase transitions of a bose gas trapped in an optical lattice as a function of effective scattering length $a_{\eff}$ and temperature $T$. Knowledge of recent high-loop results on the shift of the critical temperature at weak couplings is used to locate a {\em nose} in the phase diagram above the free Bose-Einstein critical temperature $T_c^{(0)}$, thus predicting the existence of a reentrant transition {\em above} $T_c^{(0)}$, where a condensate should form when {\em increasing} $a_{\eff}$. At zero temperature, the transition to the normal phase produces the experimentally observed Mott insulator.
Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html