共查询到18条相似文献,搜索用时 156 毫秒
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提出了一种用一对金属平板电容器和4根半埋入绝缘介质的杆电极组成的用于囚禁处于弱场搜寻态的冷极性分子的静电表面阱方案。用有限元软件计算了单阱囚禁时的空间电场分布,发现芯片表面上方2.2 mm左右形成了一个三维封闭的静电阱。选用重氨(ND_3)分子作为测试分子,用经典的蒙特卡罗方法模拟了ND_3分子被装载和囚禁的动力学过程。模拟结果表明,当ND_3分子束中心速度为13m/s、装载时刻为0.576ms时,最大装载效率可达53%,被囚禁的冷极性分子的温度约为35mK;如果继续增大平板电极的电压,则原先的单阱将对称分裂为两个阱,两个阱中的分子数目比为1…1;通过改变中间两个杆电极的电压,可实现非对称分裂,以此来调节两阱中囚禁分子数目比;可实现在0%~100%范围内左阱和右阱的分子数目占总分子数目的比例的调节。该方案为进一步研究三维囚禁型冷极性分子静电表面干涉仪打下基础,对于精密测量和研究物质波干涉有着重要的意义。 相似文献
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提出一种使用带电金属环和六个球电极和一个外加偏置电场实现对冷极性分子静电囚禁的新方案.计算装载和囚禁时空间电场分布.囚禁中心距离芯片表面的高度可以通过外电场和环形电极所加电压来操控.蒙特卡罗模拟表明对于中心速度为15 m·s-1的ND3分子束,装载效率可以达到70%,得到冷分子的温度大约为45 mK.当继续增加偏置电场强度时,单阱分裂为对称的两个阱.如果同时改变球形电极上所加电压,得到不对称的两个阱,可以借此来调节两个阱中所囚禁的冷分子数目的比例.为了易于理解,用蒙特卡罗方法模拟了装载、囚禁、分裂冷分子波包的动力学过程. 相似文献
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提出了一种利用单光束照明二元π相位板与透镜组合系统实现冷原子或冷分子囚禁的可控制光学四阱新方案.计算了四阱的光强分布,讨论了从光学四阱到双阱或到单阱的演化过程,并导出了四阱和双阱几何参数、光强分布、强度梯度及其曲率与光学透镜系统参数间的解析关系.研究表明,通过相对移动二元π相位板可实现光学四阱到双阱或到单阱的连续双向演化,获得了四阱或双阱间距与相位板移动距离的关系.该方案在超冷原子物理、冷分子物理、原子光学、分子光学和量子光学,甚至量子计算及信息处理等领域中有着广阔的应用前景.
关键词:
二元π相位板
可控制光学四阱
原子分子囚禁
原子光学 相似文献
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《光学学报》2017,(6)
提出了一种用一对金属平板电容器和4根半埋入绝缘介质的杆电极组成的用于囚禁处于弱场搜寻态的冷极性分子的静电表面阱方案。用有限元软件计算了单阱囚禁时的空间电场分布,发现芯片表面上方2.2 mm左右形成了一个三维封闭的静电阱。选用重氨(ND_3)分子作为测试分子,用经典的蒙特卡罗方法模拟了ND_3分子被装载和囚禁的动力学过程。模拟结果表明,当ND_3分子束中心速度为13m/s、装载时刻为0.576ms时,最大装载效率可达53%,被囚禁的冷极性分子的温度约为35mK;如果继续增大平板电极的电压,则原先的单阱将对称分裂为两个阱,两个阱中的分子数目比为1…1;通过改变中间两个杆电极的电压,可实现非对称分裂,以此来调节两阱中囚禁分子数目比;可实现在0%~100%范围内左阱和右阱的分子数目占总分子数目的比例的调节。该方案为进一步研究三维囚禁型冷极性分子静电表面干涉仪打下基础,对于精密测量和研究物质波干涉有着重要的意义。 相似文献
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We propose a novel scheme in which cold polar molecules are trapped
by an electrostatic field generated by the combination of a pair of
parallel transparent electrodes (i.e., two infinite transparent
plates) and a ring electrode (i.e., a ring wire). The spatial
distributions of the electrostatic fields from the above charged wire
and the charged plates and the corresponding Stark potentials for
cold CO molecules are calculated; the dependences of the trap centre
position on the geometric parameters of the electrode are analysed.
We also discuss the loading process of cold molecules from a cold
molecular beam into our trap. This study shows that the proposed
scheme is not only simple and convenient to trap, manipulate and
control cold polar molecules in weak-field-seeking states, but also
provides an opportunity to study cold collisions and collective
quantum effects in a variety of cold molecular systems, etc. 相似文献
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提出了一种新的采用载流导线的表面双磁光阱(MOT)方案(即双U型导线磁光阱方案)。通过改变中间U型导线中的电流大小,即可将一个双磁阱连续地合并为一个单磁阱,反之亦然。详细计算和分析了上述双U型载流导线磁光阱方案的磁场及其梯度的空间分布,研究发现当导线中的电流为600 A,z方向均匀偏置磁感应强度为-4.0×10-3 T时,双U型导线方案产生的两个磁阱中心的磁场梯度约为1.5×10-3~2.5×10-3 T/cm,结合通常制备磁光阱时所用的三维粘胶(Molasses)光束即可在基底表面附近形成一双磁光阱。理论分析表明在弱光近似下,每个磁光阱中所能俘获的85Rb原子数约为106 量级,相应的磁光阱温度约为270μK。由于双磁光阱可以独立制备,所以双U型导线方案特别适用于制备双样品磁光阱,并用于研究双原子样品的冷碰撞性质。 相似文献
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提出了一种新颖的实现冷原子(或冷分子)囚禁的可控制纵向光学双阱方案,它由一个二元π相位板及一会聚透镜所组成,其π相位板由两个面积相等的具有0和π相位的同心圆环组成. 当一平面光波通过此光学系统时将在光轴上透镜焦点两侧形成一个光学双阱,如果调节入射到二元π相位板上光束横截面的半径大小,即可实现从光学双阱到单阱的连续演变,或由单阱到双阱的连续变化. 介绍了本方案产生可控制光学双阱的基本原理,给出了形成光学双阱的最佳几何参数,研究了双阱、单阱及其演化过程的光阱参数、光强分布等与光学系统参数间的关系. 该方案不仅可用于双样品原子(分子)的光学囚禁及其全光型玻色-爱因斯坦凝聚(BEC)的实现,而且可用于研究超冷原子(或分子)物质波的干涉,或构成双层2D光阱列阵,甚至用于制备新颖的双层2D光学晶格.
关键词:
二元π相位板
可控制光学双阱
双样品囚禁
光学晶格 相似文献
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We propose a simple scheme for trapping cold polar molecules in low-field seeking states on the surface of a chip by using a grounded metal plate and two finite-length charged wires that half embanked in an insulating substrate, calculate the electric field distributions generated by our charged-wire layout in free space and the corresponding Stark potentials for ND3 molecules, and analyze the dependence of the trapping center position on the geometric parameters. Moreover, the loading and trapping processes of cold ND3 molecules are studied by using the Monte Carlo method. Our study shows that the loading efficiency of the trap scheme can reach 11.5%, and the corresponding temperature of the trapped cold molecules is about 26.4 mK. 相似文献
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R. W. Mu Z. L. Wang Y. L. Li X. M. Ji J. P. Yin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,59(2):291-300
We experimentally demonstrate a practical scheme to form a controllable
double-well optical dipole trap for cold atoms (or cold molecules), and give
some experimental results as well as the fabrication method of a binary
π-phase plate. The dependence of the double-well characteristics on the phase
etching error of the π-phase plate and the evolution of the double-well
optical trap from two wells to a single one are studied both theoretically
and experimentally, and the experimental results are consistent with the
theoretical prediction. Furthermore, the dynamic process of loading and
splitting of cold 87Rb atoms from a standard magneto-optical trap (MOT)
into our controllable double-well one are studied by Monte Carlo
simulations. Our study shows that the loading efficiency of cold atoms from
the standard MOT into our single-well trap can reach 100%, and the
relative atomic density will be reduced from 1.0 to ∼0.5 during the
evolution of our double-well trap, in which the temperature of cold atoms is
reduced from 20 μK to ∼15 μK. In final, some potential
applications of our controllable double-well optical trap in atom and
molecule optics are briefly discussed. 相似文献
17.
Stark-potential evaporative cooling of polar molecules in a novel optical-access opened electrostatic trap
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《中国物理 B》2015,(11)
We propose a novel optical-access opened electrostatic trap to study the Stark-potential evaporative cooling of polar molecules by using two charged disk electrodes with a central hole of radius r0= 1.5 mm, and derive a set of new analytical equations to calculate the spatial distributions of the electrostatic field in the above charged-disk layout. Afterwards, we calculate the electric-field distributions of our electrostatic trap and the Stark potential for cold ND3 molecules, and analyze the dependences of both the electric field and the Stark potential on the geometric parameters of our charged-disk scheme,and find an optimal condition to form a desirable trap with the same trap depth in the x, y, and z directions. Also, we propose a desirable scheme to realize an efficient loading of cold polar molecules in the weak-field-seeking states, and investigate the dependences of the loading efficiency on both the initial forward velocity of the incident molecular beam and the loading time by Monte Carlo simulations. Our study shows that the maximal loading efficiency of our trap scheme can reach about 95%, and the corresponding temperature of the trapped cold molecules is about 28.8 m K. Finally, we study the Stark-potential evaporative cooling for cold polar molecules in our trap by the Monte Carlo method, and find that our simulated evaporative cooling results are consistent with our developed analytical model based on trapping-potential evaporative cooling. 相似文献
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Theoretical derivation and simulation of a versatile electrostatic trap for cold polar molecules
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We propose a versatile electrostatic trap scheme using several charged spherical electrodes and a bias electric held.We hrst give the two-ball scheme and derive the analytical solution of the electric held.In order to make a comparison,we also give the numerical solution calculated by the hnite element software(Ansoft Maxwell).Considering the loading of cold polar molecules into the trap,we give the three-ball scheme.We hrst give the analytical and numerical solutions of the distribution of the electric held.Then we simulate the dynamic process of the loading and trapping cold molecules using the classical Monte Carlo method.We analyze the influence of the velocity of the incident molecular beam and the loading time on the loading efficiency.After that,we give the temperature of the trapped cold molecules.Our study shows that the loading efficiency can reach 82%,and the corresponding temperature of the trapped molecules is about 24.6 mK.At last,we show that the single well divides into two ones by increasing the bias electric held or decreasing the voltages applied to the spherical electrodes. 相似文献