Interaction of atoms with twisted light is the subject of intense experimental and theoretical investigation. In almost all studies, the atom is viewed as a localized probe of the twisted light field. However, as argued in this paper, conceptually novel effects will arise if light-atom interaction is studied in the double-twisted regime with delocalized atoms, that is, either via twisted light absorption by atom vortex beam, or via two-twisted-photon spectroscopy of atoms in a non-vortex but delocalized state. Even for monochromatic twisted photons and for an infinitely narrow line, absorption will occur over a finite range of detuning. Inside this range, a rapidly varying absorption probability is predicted, revealing interference fringes induced by two distinct paths leading to the same final state. The number, location, height, and contrast of these fringes can give additional information on the excitation process which would not be accessible in usual spectroscopic settings. Visibility of the predicted effects will be enhanced at the future Gamma factory thanks to the large momenta of ions.

中文翻译：

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具有离域原子的双扭曲光谱

原子与扭曲光的相互作用是激烈的实验和理论研究的主题。在几乎所有研究中，原子都被视为扭曲光场的局部探针。然而，如本文所述，如果在具有离域原子的双扭曲方案中研究光原子相互作用，即通过原子涡旋光束的扭曲光吸收，或通过双扭曲光子，将产生概念上新颖的效果非涡旋但离域状态的原子光谱学。即使对于单色扭曲光子和无限窄的线，也会在有限的失谐范围内发生吸收。在此范围内，预计会出现快速变化的吸收概率，揭示了由两条不同路径引起的干涉条纹，导致相同的最终状态。数量，位置，高度，这些条纹的对比可以提供关于激发过程的额外信息，这在通常的光谱设置中是无法获得的。由于离子的大动量，未来 Gamma 工厂将提高预测效果的可见性。