Spin-Dipole Oscillation and Polarizability of a Binary Bose-Einstein Condensate near the Miscible-Immiscible Phase Transition

摘要

We report on the measurement of the spin-dipole (SD) polarizability and ofthe frequency of the SD oscillation of a two-component Bose-Einstein condensateof sodium atoms occupying the $|3^2S_{1/2}, F=1, m_F=\pm1\rangle$ hyperfinestates. This binary spin-mixture presents the important properties of being, atthe same time, fully miscible and rid of the limit set by buoyancy. It is alsocharacterized by a huge enhancement of the SD polarizability and by theconsequent softening of the frequency of the SD oscillation, due to thevicinity to the transition to the immiscible phase. The experimental data aresuccessfully compared with the predictions of theory.