Modifying atom-surface interactions with optical fields
Modifying atom-surface interactions with optical fields
复制标题
用光场改变原子表面相互作用
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
A. Cronin
中科院分区：
文献类型：
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作者：
J. Perreault;M. Bhattacharya;V. Lonij;A. Cronin
在纳米尺度上控制物质的能力受到货车范德华vdW相互作用的极大影响。因此，理解和操纵vdW相互作用是纳米技术和原子光学领域的兴趣。我们发现，近共振光可以显着修改原子表面vdW相互作用在nonretarded制度。基于量子化电磁场的理论被用来计算1普通的vdW相互作用，2由于热辐射的普通vdW相互作用的修正，和3普通的vdW相互作用的单色激光辐射的结果的修改。预测强度为5 W /cm 2的近共振激光对钠原子的vdW相互作用强度将增加一倍，并讨论了检测这种效应的可能实验。物质之间的货车范德华vdW相互作用的强度通常由系统的原子或体材料性质决定。因此，vdW力通常只能通过改变参与相互作用的物质的原子成分来改变，从而限制了控制纳米尺度力的能力。这种情况与vdW相互作用可以被认为是由量子力学原子1的波动偶极矩引起的观点相一致。然后，这些波动的偶极子可以相互作用，导致原子之间的vdW力。然而，存在另一种观点，其中vdW相互作用的起源是由于真空中的电磁场波动，这又在原子2中引起波动的偶极矩。这表明vdW相互作用可以受到物质所处的辐射环境的影响，从而打开了使用光来控制甚至抑制vdW相互作用的可能性。改变物质辐射环境的一种方法是通过温度，将原子暴露在热电磁场中。原则上，这应该修改vdW或Casimir-Polder相互作用。最近在延迟区3中的原子和附近表面上观察到了这种效应，其中原子-表面距离z远大于原子的主跃迁波长。然而，热修改预计是可以忽略不计的nonretarded制度4，5，其中距离是这样的z。这是不幸的，因为改变原子和表面之间的力的能力将对原子芯片、原子光学和量子反射实验产生影响。
The ability to control matter on the nanometer scale is greatly influenced by the van der Waals vdW interaction. Therefore, understanding and manipulating the vdW interaction is of interest to the fields of nanotechnology and atom optics. We show that near-resonant light can significantly modify atom-surface vdW interactions in the nonretarded regime. A theory based on quantized electromagnetic fields is used to calculate 1 the ordinary vdW interaction, 2 corrections to the ordinary vdW interaction due to thermal radiation, and 3 modifications to the ordinary vdW interaction that result from monochromatic laser radiation. Near- resonant laser light with an intensity of 5 W /cm 2 is predicted to double the vdW interaction strength for sodium atoms, and possible experiments to detect this effect are discussed. The strength of the van der Waals vdW interaction be- tween matter is usually determined by the atomic or bulk material properties of a system. Therefore, the vdW force can typically only be altered by changing the atomic constituents of the matter involved in the interaction, limiting the ability to control nanometer scale forces. This circumstance reso- nates with the point of view in which the vdW interaction can be thought of as being caused by the fluctuating dipole moment of a quantum-mechanical atom 1. These fluctuat- ing dipoles can then interact with each other, leading to the vdW force between the atoms. However, there exists an al- ternative perspective in which the origin of the vdW interac- tion is due to electromagnetic-field fluctuations in the vacuum, which in turn induce a fluctuating dipole moment in the atoms 2. This suggests that the vdW interaction can be affected by the radiation environment that the matter resides in, opening the exciting possibility of using light to control or even inhibit the vdW interaction. One way to change the radiation environment of matter is through temperature, which exposes the atoms to a thermal electromagnetic field. In principle, this should modify the vdW or Casimir-Polder interaction. Just such an effect has recently been observed for an atom and a nearby surface in the retarded regime 3, where the atom-surface distance z is much larger than the principle transition wavelength of the atom. However, thermal modifications are predicted to be negligible in the nonretarded regime 4,5, where distances are such that z. This is unfortunate since the ability to change the force between atoms and a surface would have an impact on atom chips, atom optics, and quantum reflection experiments.