论文标题
观察强铁磁纺纱厂凝结物
Observation of a strongly ferromagnetic spinor Bose-Einstein condensate
论文作者
论文摘要
我们报告了强烈的铁磁$ f = 1 $旋转玻璃纤维凝结物为$^7 $ li原子的观察。冷凝物是在光学偶极子陷阱中生成的，而无需使用磁性feshbach谐振，因此冷凝物具有内部自然自由度。研究非平衡自旋动力学，我们测量了铁磁旋转相互作用能，并确定了总自旋$ f $通道之间的$ s $ - 波散射长度差，为$ a_ {f = 2} -a_ {f = 0} = -18（3）$ bohr radius。这种强烈的碰撞通道依赖性导致凝结物尺寸的较大变化，并具有不同的自旋组成。在$ | m_f = 0 \ rangle $和$ | m_f = 1 \ rangle $ spin状态之间，我们能够激发径向单极模式。从实验中，我们估计散射长度比$ a_ {f = 2}/a_ {f = 0} = 0.27（6）$，并确定$ a_ {f = 2} $ = 7（2）和$ a_ {f = 0} $ = 25（5）bohr radii。结果表明，我们系统的自旋依赖性相互作用能量高达冷凝物化学势的46 $ \％$。
We report the observation of strongly ferromagnetic $F=1$ spinor Bose-Einstein condensates of $^7$Li atoms. The condensates are generated in an optical dipole trap without using magnetic Feshbach resonances, so that the condensates have internal spin degrees of freedom. Studying the non-equilibrium spin dynamics, we have measured the ferromagnetic spin interaction energy and determined the $s$-wave scattering length difference among total spin $f$ channels to be $a_{f=2}-a_{f=0} =-18(3)$ Bohr radius. This strong collision-channel dependence leads to a large variation in the condensate size with different spin composition. We were able to excite a radial monopole mode after a spin-flip transition between the $|m_F=0\rangle$ and $|m_F=1\rangle$ spin states. From the experiments, we estimated the scattering length ratio $a_{f=2}/a_{f=0}=0.27(6)$, and determined $a_{f=2}$ = 7(2) and $a_{f=0}$ = 25(5) Bohr radii, respectively. The results indicate the spin-dependent interaction energy of our system is as large as 46$\%$ of the condensate chemical potential.
