ua nt - p h / 99 08 06 8 v 2 2 6 D ec 1 99 9 Two dimensional nonlinear dynamics of evanescent - wave guided atoms in hollow fiber

We describe the classical and quantum two dimensional nonlinear dynamics of large blue-detuned evanescent-wave guiding cold atoms in hollow fiber. We show that chaotic dynamics exists for classic dynamics, when the intensity of the beam is periodically modulated. The two dimensional distributions of atoms in (x, y) plane are simulated. We show that the atoms will accumulate on several annular regions when the system enters a regime of global chaos. Our simulation shows that, when the atomic flux is very small, a similar distribution will be obtained if we detect the atomic distribution once each the modulation period and integrate the signals. For quantum dynamics, quantum collapses and revivals appear. For periodically modulated optical potential, the variance of atomic position will be suppressed compared to the no modulation case. The atomic angular momentum will influence the evolution of wave function in two dimensional quantum system of hollow fiber.