Emergence of Bloch bands in a rotating Bose-Einstein condensate

梁兆新, 胡斑比

Tobias Klafka, Alexander Ilin, Julius Seeger +3 more

Hiroki Saito, Masahito Ueda

A rotating Bose-Einstein condensate is shown to exhibit a Bloch band structure even in the absence of a periodic potential. Vortices enter the condensate via Bragg reflection if the frequency of a rotating drive is adiabatically increased or decreased, or if the interaction is adiabatically changed at a constant rotating drive. A localized state analogous to a gap soliton in a periodic system is predicted to occur near the edge of the Brillouin zone.

Biao Wu, Roberto B. Diener, Qian Niu

Bloch waves and Bloch bands of Bose-Einstein condensates in optical lattices are studied. We provide further evidence for the loop structure in the Bloch band, and compute the critical values of the mean-field interaction strength for the Landau instability and the dynamical instability.

Sayan Choudhury, Erich J. Mueller

Liang Zhao-Xin, Hu Ban-Bi

Landau and dynamical instabilities of a Bose–Einstein condensate (BEC) in the excited bands of a one-dimensional optical lattice are investigated by the Gross–Pitaevskii theory. Our results show that there always exists Landau instability for a BEC in the whole region of excited bands. We also map out the dangerous zones of the dynamical instability. The experimental implications of the stability diagram are discussed.