LAUSR

In this paper, the critical rotation rate for vortex nucleation in ultracold rotating boson atoms in 2D deep optical lattices is calculated. We suggest a semiclassical approach to calculate the critical rotation frequency at finite temperature through extension of Stringari threshold formula. The critical rotation frequency is parametrized in terms of the thermodynamic potential. Depending on the semiclassical approximation, the calculated thermodynamic potential enabled us to investigate the finite size and interatomic interaction effects. The calculated results show that the critical rotation rate, as a function of stirring frequency, shows a peak, while the critical rotation rate as a function of the normalized temperature decreases monotonically with the increase in the temperature. The critical rotation rate depends on the interatomic interaction, atoms number and optical potential depth. The obtained results provide useful theoretical foundation for rotating condensate boson in optical lattice.