Abstract:

At the beginning of the talk, I will give a brief review of the state of the art in the field of twisted photons. The main definitions and notation will also be given. Then I will present a review of the results of our scientific group regarding the means for generation of twisted photons and the interaction of twisted photons with excitons in semiconductor films and atomic nuclei. Among the ways of generation of twisted photons there will be considered: undulator radiation, nonlinear Compton process, transition and Vavilov-Cherenkov radiations (both in the classical setup and for helical beams and media), reflection from helical media (for example, from a cholesteric liquid crystal). The probabilities of transitions induced by twisted photons in the Wannier excitons and the Coulomb centers in thin semiconductor films will be derived. Furthermore, the probability of photoabsorption of twisted photons by atomic nuclei will be obtained. The selection rules for these processes will be deduced.