Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
Phys Rev Lett. 2011 Nov 4;107(19):190401. doi: 10.1103/PhysRevLett.107.190401. Epub 2011 Oct 31.
We report the Bose-Einstein condensation (BEC) of the most magnetic element, dysprosium. The Dy BEC is the first for an open f-shell lanthanide (rare-earth) element and is produced via forced evaporation in a crossed optical dipole trap loaded by an unusual, blue-detuned and spin-polarized narrowline magneto-optical trap. Nearly pure condensates of 1.5 × 10(4) (164)Dy atoms form below T = 30 nK. We observe that stable BEC formation depends on the relative angle of a small polarizing magnetic field to the axis of the oblate trap, a property of trapped condensates only expected in the strongly dipolar regime. This regime was heretofore only attainable in Cr BECs via a Feshbach resonance accessed at a high-magnetic field.
我们报告了最具磁性元素镝的玻色-爱因斯坦凝聚（BEC）。Dy BEC 是第一个开放 f 壳层镧系元素（稀土）的 BEC，是通过在 crossed optical dipole trap 中强制蒸发产生的，该 trap 由一个不寻常的、蓝失谐和自旋极化的 narrowline magneto-optical trap 加载。在 T = 30 nK 以下形成了近纯的 1.5×10(4)（164）Dy 原子的凝聚物。我们观察到，稳定的 BEC 形成取决于小极化磁场相对于扁长形 trap 轴的相对角度，这是仅在强偶极子区域才预期的被俘获凝聚物的性质。这个区域迄今为止只能通过在高磁场下通过 Feshbach 共振获得的 Cr BEC 来实现。
