Physikalisches Institut, Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany.
Physikalisches Institut, Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
Phys Rev Lett. 2014 Jun 27;112(25):250404. doi: 10.1103/PhysRevLett.112.250404. Epub 2014 Jun 25.
We observe two consecutive heteronuclear Efimov resonances in an ultracold Li-Cs mixture by measuring three-body loss coefficients as a function of magnetic field near a Feshbach resonance. The first resonance is detected at a scattering length of a_((0))=-320(10)a_((0)), corresponding to ∼7(∼3) times the Li-Cs (Cs-Cs) van der Waals range. The second resonance appears at 5.8(1.0)a_((0)), close to the unitarity-limited regime at the sample temperature of 450 nK. Indication of a third resonance is found in the atom loss spectra. The scaling of the resonance positions is close to the predicted universal scaling value of 4.9 for zero temperature. Deviations from universality might be caused by finite-range and temperature effects, as well as magnetic field-dependent Cs-Cs interactions.
我们通过测量磁场附近的三体损失系数，在一个超冷的锂-铯混合物中观察到两个连续的异核 Efimov 共振。第一个共振在散射长度 a_((0))=-320(10)a_((0))处被检测到，对应于约 7(∼3)倍的锂-铯（铯-铯）范德瓦尔斯范围。第二个共振出现在 5.8(1.0)a_((0))处，接近在 450 nK 的样品温度下的单位极限状态。在原子损失谱中发现了第三个共振的迹象。共振位置的标度接近零温下预测的通用标度值 4.9。非普遍性偏差可能是由有限范围和温度效应以及磁场依赖的铯-铯相互作用引起的。
