Interaction of twisted light with individual atoms and atomic ensembles

• Applicant: Professor Dr. Andrey Surzhykov
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 445408588

Over the past decades, significant attention has been paid to the production and application of twisted light, exhibiting phase singularities, highly inhomogeneous intensity profiles and complex polarization textures. For example, twisted light modes have proven to be a valuable tool in super-resolution microscopy, classical and quantum communication, and as optical tweezers. In addition, interactions of twisted radiation with single atoms and atomic ensembles are also in the focus of intense research. The theoretical investigation of such interactions was the goal of the first funding period of this project. We have studied how twisted light can be used to generate matter wave vortices in Bose-Einstein condensates and effectively excite narrow-line clock transitions in trapped ions. The successful realization of the research program, supported by close cooperation with theoretical and experimental groups from Germany and from all over the world, has brought new challenges that are planned to be dealt with in the second funding period of the project. In particular, we aim to perform a rigorous analysis of the interaction of twisted light with a trapped atom under realistic experimental parameters and arbitrary geometries. This study is of great importance for the further development of high-precision optical clocks and integrated photonics. We will also address a highly intriguing question of large transverse momentum transfer to a target atom exposed to twisted radiation, known in the field as the superkick effect. Moreover, it will be investigated how the transfer of angular momentum to the atom's center of mass can be used in quantum detectors, which may have important implications for metrology. To advance theoretical research on these and other topics mentioned in the proposal, we apply here for the second funding period.

• DFG Programme: Research Grants