Salam A
Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109-7486, USA.
J Chem Phys. 2006 Jan 7;124(1):14302. doi: 10.1063/1.2140000.
The change in the mutual energy of interaction between a pair of chiral molecules coupled via the exchange of a single virtual photon and in the presence of an electromagnetic field is calculated using nonrelativistic quantum electrodynamics. The particular viewpoint adopted is one that has an intuitive physical appeal and resembles a classical treatment. It involves the coupling of electric and magnetic dipole moments induced at each center by the incident radiation field to the resonant dipole-dipole interaction tensor. The energy shift is evaluated for fixed as well as random orientations of the molecular pair with respect to the direction of propagation of the field. A complete polarization analysis is carried out for the former situation by examining the effect of incident radiation that is linearly or circularly polarized and traveling in a direction that is parallel or perpendicular to the intermolecular distance vector. After tumble averaging, all polarization dependence of the energy shift vanishes. In both cases the interaction energy is directly proportional to the irradiance of the applied field, and is discriminatory, changing sign when one optically active species is replaced by its enantiomer. The asymptotic behavior of the energy shift at the limits of large and small separations is also studied.
利用非相对论量子电动力学计算了在单个虚光子交换且存在电磁场的情况下，一对通过该交换耦合的手性分子之间相互作用能的变化。所采用的特定观点具有直观的物理吸引力，类似于经典处理方法。它涉及由入射辐射场在每个中心诱导的电偶极矩和磁偶极矩与共振偶极 - 偶极相互作用张量的耦合。对于分子对相对于场传播方向的固定取向以及随机取向，都对能量 shift 进行了评估。对于前一种情况，通过检查线性或圆偏振且沿平行或垂直于分子间距离矢量方向传播的入射辐射的影响，进行了完整的偏振分析。经过翻滚平均后，能量 shift 的所有偏振依赖性都消失了。在这两种情况下，相互作用能都与所施加场的辐照度成正比，并且具有区分性，当一种旋光性物质被其对映体取代时，符号会改变。还研究了在大分离和小分离极限下能量 shift 的渐近行为。
