Near-field optical potential for a neutral atom
Near-field optical potential for a neutral atom
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中性原子的近场光势
DOI：
10.1103/physreva.63.013806
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发表时间：
2000
影响因子：
2.9
通讯作者：
M. Ohtsu
中科院分区：
文献类型：
--
作者：
K. Kobayashi;S. Sangu;H. Ito;M. Ohtsu
我们研究光学近场系统中中性原子和纳米探针尖端之间的有效相互作用势。激子极化子耦合系数的波数依赖性用有效质量近似来描述，其中大量虚拟光子在原子和探针尖端之间交换。近场光势表现为几种有效质量或相互作用范围的汤川函数之和，并用原子和探针尖端的共振能量失谐来表征。因此，我们发现蓝色失谐情况产生了潜在的最小值。这一结果表明原子可以被捕获在近场光学势阱中。此外，我们通过纳米探针尖端产生的光学近场对单个原子的偏转和捕获进行数值研究。阐明了对探针尖端尺寸、冷原子动能以及探针尖端和原子的激发能的依赖性。
We study an effective interaction potential between a neutral atom and a nanometric probe tip in optical near-field systems. The wave-number dependence of the coupling coefficients of exciton polaritons is described with the effective-mass approximation, where massive virtual photons are exchanged between the atom and the probe tip. The near-field optical potential is shown as the sum of the Yukawa functions with several kinds of effective masses or interaction ranges, and is characterized in terms of detuning for the resonance energies of the atom and the probe tip. Consequently, we find that a potential minimum is produced for a blue detuning case. This result indicates that an atom can be trapped in the near-field optical potential well. Furthermore, we numerically investigate deflection and trapping of a single atom by means of optical near fields generated from a nanometric probe tip. The dependence on the probe-tip size, the kinetic energy of the cold atom, and the excitation energies of both probe tip and atom is clarified.