When polarized light is absorbed by an atom, the excited atomic system carries information about the initial polarization of light. For the light that carries an orbital angular momentum, or the twisted light, the polarization states are described by eight independent parameters, as opposed to three Stokes parameters for plane waves. We use a parameterization of the spin-density matrix of the twisted light in terms of vector and tensor polarization, in analogy with massive spin-1 particles, and derive formulae that define atom's response to specific polarization components of the twisted light. It is shown that for dipole ($S\to P$) atomic transitions, the atom's polarization is in one-to-one correspondence with polarization of the incident light; this relation is violated, however, for the transitions of higher multipolarity ($S\to D$, $S\to F$, etc.) We pay special attention to contributions of the longitudinal electric field into the matrix elements of atomic transitions.

中文翻译：

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从扭曲光到原子的偏振转移

当偏振光被原子吸收时，被激发的原子系统携带有关光初始偏振的信息。对于携带轨道角动量的光或扭曲光，偏振态由八个独立参数描述，而不是平面波的三个斯托克斯参数。我们在矢量和张量极化方面使用扭曲光的自旋密度矩阵的参数化，类似于大质量自旋 1 粒子，并推导出定义原子对扭曲光的特定偏振分量的响应的公式。结果表明，对于偶极（$S\to P$）原子跃迁，原子的偏振与入射光的偏振一一对应；然而，对于更高的多极（$S\to D$，