一个新的四维混沌系统理论分析与电路实现

分析了一个新的复杂的四维混沌系统的基本特性，该系统每个方程中包含一个三次交叉乘积项，共有9个平衡点，它们相对于原点和坐标轴具有完美的对称性，并且相对于线性特性和不变流形具有很好的相似性.描述了两个同时共存的对称双翼吸引子.最后，设计了一个模拟电路来实现这个新的四维混沌系统，表明数值仿真和电路实现具有很好的一致性，同时说明在应用上由于频率不同导致的仿真与物理实现之间的重要区别. 关键词： 四维混沌系统 Lyapunov 指数 共存双翼吸引子 电路实现     

磁光阱中超冷钠-铯原子碰撞的实验研究

研究了磁光阱中异核超冷钠铯原子的碰撞机理, 测量了超冷钠原子的碰撞损失率, 得到了钠-铯原子的碰撞损失系数β_Na-Cs与钠原子俘获光强度之间的关系. 利用多普勒模型计算了不同俘获光强度下的钠原子磁光阱的阱深, 得到了临界光强的理论值, 与实验结果符合得较好.     

High efficient Raman sideband cooling and strong three-body recombination of atoms

We report a highly efficient three-dimensional degenerated Raman sideband cooling(3D dRSC) that enhances the loading of a magnetically levitated optical dipole trap, and observe the strong atom loss due to the three-body recombination.The 3D dRSC is implemented to obtain 5×10⁷ Cs atoms with the temperature of ～ 480 nK. The cold temperature enables 1.8×10⁷ atoms loaded into a crossed dipole trap with an optimized excessive levitation magnetic gradient. Compared to the loadin...     

超冷铯分子0u+(6P3/2)长程态的高灵敏光缔合光谱研究

利用发展的调制俘获损耗荧光光谱技术实验测量了超冷铯分子0_u⁺(6P_3/2)长程态的高灵敏光缔合光谱. 光谱探测范围较国际已有报道扩大了60 cm^-1, 观察到25个长程区域新的振动能级. 通过LeRoy-Bernstein公式对振动束缚能数据进行拟合, 获得了超冷铯分子0_u⁺(6P_3/2)态的长程系数C₃ 为16.103±0.010. 构建了超冷铯分子0_u⁺(6P_3/2)态长程区域的势能曲线.     

Spin current in a spinor Bose-Einstein condensate induced by a gradient magnetic field

We develop a research of spin currents in a ²³Na spinor Bose-Einstein condensate (BEC) by applying a magnetic field gradient. The spin current is successfully induced by the spin-dependent force arising from the magnetic field gradient. The dynamics of the spin components under the magnetic force is investigated. The study is promising to be extended to produce a longer spin-coherence and to enhance the sensitivity of the spin-mixing interferometry in a spinor BEC.     

Highly sensitive photoassociation spectroscopy of ultracold ~(23)Na~(133)Cs molecular long-range states below the 3S_(1/2)+6P_(3/2)limit

We present high resolution photoassociation spectroscopy of ultracold~(23)Na~(133)Cs molecules in a long-range c~3Σ~+state below the(3 S_(1/2)+ 6 P_(3/2)) asymptote. We perform photoassociation spectroscopy in a dual-species magneto-optical trap(MOT) and detect the photoassociation resonances using trap-loss spectroscopy. By fitting the experimental data with the semi-classical Le Roy–Bernstein formula, we deduce the long-range molecular coefficient C6 and derive the empirical potential energy curve in the long-range region.     

原子量的碳-12标准

本文主要介绍碳-12为原子量的标准及碳-12标准的国际原子量较之原来的国际原子量的变动情况如何。为了说明这些问题,本文拟就下列几点作简要讨论和介绍:(1)两种原子量标准的共存;(2)统一两种原子量标准的必要性;(3)在什么基础上将两种原子量标准统一起来;(4)采用碳-12=12为统一的原子量标准。     

超冷铯分子纯长程态转动常数的精密测量

利用调制的俘获损耗光谱技术实验测量了超冷铯分子纯长程0_g^-态的高分辨光谱. 采用双光缔合光谱技术构建了精确的频率差参考信号, 对转动能级的共振频率间隔进行了精确的标定, 获得了转动能级频率间隔与转动量子数的关系. 通过将实验数据拟合到非刚性转动模型, 获得了超冷铯分子纯长程0_g^-态不同振动态的转动常数. 实验结果表明转动常数随振动量子数的增加而线性减小, 线性递减率为-0.41 MHz±0.01 MHz. 关键词： 双光缔合光谱技术 超冷铯分子 转动常数 纯长程态     

High-resolution photoassociation spectroscopy of ultracold Cs2 long-range 0-g state： The external well potential depthHigh-resolution photoassociation spectroscopy of ultracold Cs2 long-range 0-g state： The external well potential depthHigh-resolution photoassociation spectroscopy of ultracold Cs2 long-range 0-g state： The external well potential depth

High-resolution photoassociation spectroscopy is reported using a modulation spectroscopy technology in a cesium atomic magneto-optical trap. The two lowest vibrational levels have been experimentally observed which have been theo- retically predicted in [Phys. Rev. A 75 052501 （2007）]. A new potential curve is obtained by using the Rydberg-Klein-Ress method with a well depth of -82,384 ＋ 0,026 cm-1, which is deeper than the result of previous experiment （-77.909 cm-1） and the theoretical prediction （-81.6445 cm- l ）.     

High-resolution photoassociation spectroscopy of ultracold Cs2 long-range 0g- state：The external well potential depth

High-resolution photoassociation spectroscopy is reported using a modulation spectroscopy technology in a cesium atomic magneto-optical trap. The two lowest vibrational levels have been experimentally observed which have been theoretically predicted in [Phys. Rev. A 75 052501(2007)]. A new potential curve is obtained by using the Rydberg–Klein–Ress method with a well depth of 82.384±0.026 cm-1, which is deeper than the result of previous experiment( 77.909 cm-1) and the theoretical prediction( 81.6445 cm-1).