2017/03/31 by Xiaoning Zang, Mark T. Lusk · 12 citations
Physics and Astronomy · #Angular momentum #Angular momentum coupling #Angular momentum of light #Angular momentum operator #Beam (structure) #Classical mechanics #Cold Atom Physics and Bose-Einstein Condensates #Exciton #Optics #Orbital angular momentum multiplexing #Orbital angular momentum of light #Paraxial approximation #Physics #Quantum mechanics #Quantum optics and atomic interactions #Spectroscopy and Quantum Chemical Studies #Total angular momentum quantum number #physics.atm-clus #physics.optics
paper · pdf · doi:10.1103/physreva.96.013819
published in Physical Review A 96(1) (American Physical Society) · 29 pages, 13 figures
openalex created_date 2017/03/16 · arxiv created 2017/06/13 · openalex publication_date 2017/07/11 · arxiv updated 2017/08/02 · openalex updated_date 2026/08/05
Molecules with CN or CNh symmetry can absorb quanta of optical angular momentum to generate twisted excitons with well-defined quasiangular momenta of their own. Angular momentum is conserved in such interactions at the level of a paraxial approximation for the light beam. A sequence of absorption events can thus be used to create a range of excitonic angular momenta. Subsequent decay can produce radiation with a single angular momentum equal to that accumulated. Such molecules can thus be viewed as mediators for changing the angular momentum of light. This sidesteps the need to exploit nonlinear light-matter interactions based on higher-order susceptibilities. A tight-binding paradigm is used to verify angular momentum conservation and demonstrate how it can be exploited to change the angular momentum of light. The approach is then extended to a time-dependent density functional theory setting where the key results are shown to hold in a many-body, multilevel setting.