Double-twisted spectroscopy with delocalized atoms

TL;DR

This paper explores novel effects in light-atom interactions using double-twisted regimes with delocalized atoms, predicting interference fringes in absorption spectra that reveal new quantum information.

Contribution

It introduces the concept of double-twisted spectroscopy with delocalized atoms, highlighting effects not observable in traditional localized atom studies.

Findings

Finite detuning range for absorption with interference fringes

Interference fringes depend on two-path quantum interference

Enhanced visibility at future Gamma factory facilities

Abstract

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.