title: Strong local-field effect on the dynamics of a dilute atomic gas irradiated by two counterpropagating optical fields: beyond standard optical lattices.
abstract: We study a recent experiment [K. Li et al., Phys. Rev. Lett. 101, 250401 (2008)] on diffracting a Bose-Einstein condensate by two counterpropagating optical fields. Including the local-field effect, we explain the asymmetric momentum distribution and self-imaging of the Bose-Einstein condensate self-consistently. Moreover, we find that the two counterpropagating optical fields could not produce a perfect optical lattice, which is actually deformed by the local-field effect. Our work implies that the local-field effect could be essential for getting a better quantitative analysis of other optical lattice experiments. In particular, the intensity imbalance of the two optical fields could act as a new means to tailor both cold atom dynamics and light propagation.
authors.affiliation: State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhu
authors.forename: Guangjiong
authors.initials: G
authors.lastname: Dong
authors.forename: Mikhail N
authors.initials: MN
authors.lastname: Shneider
authors.forename: Weiping
authors.initials: W
authors.lastname: Zhang