Manipulating atomic states via optical orbital angular-momentum

Rafael Alves De Oliveira, Gabriel C. Borba, Weliton Soares Martins +3 more

We report on the demonstration of a nonlinear optical memory (NOM) for storage and on-demand manipulation of orbital angular momentum (OAM) of light via higher-order nonlinear processes in cold cesium atoms. A spatially resolved phase-matching technique is used to select each order of the nonlinear susceptibility associated, respectively, with time-delayed four-, six-, and eight-wave mixing processes. For a specific configuration of the stored OAM of the incident beams, we demonstrated that the OAM of the retrieved beam can be manipulated according to the order of the nonlinear process chosen by the operator for reading out the NOM. This demonstration indicates new pathways for applications in classical and quantum information processing where OAM of light is used to encode optical information.

Antonio Miguel Pico, Calvo

William D. Phillips

D. Moretti, D. Felinto, J. W. R. Tabosa

The paper reports on the storage of superposition of orbital angular momentum (OAM) states, as well as its manipulation through an applied transverse magnetic field. In the experiment , Zeeman sublevels of the degenerate two-level system is used. In another series of experiments,an external dc magnetic field is applied, nearly orthogonal to the plane defined by the incident beams. In this case,a series of collapses and revivals of the stored Zeeman coherence is observed. These observations demonstrate that superposition of OAM states can be stored into the atomic ensemble, and also the reversible transfer of OAM between light and atoms. Moreover, it also shows that the stored OAM can be manipulated with an external magnetic field.

Eleonora Nagali, Vincenzo D’Ambrosio, Lorenzo Marrucci +1 more

The orbital angular momentum carried by single photons represents a promising resource in the quantum information field. In this paper we report a series of optical schemes adopted for the manipulation of quantum states encoded in the orbital angular momentum exploiting the q-plate device. We further demonstrate the capability of generating hybrid entangled states as well as quantum states in dimension higher than two. Indeed we present the manipulation of ququart states encoded in the polarization and orbital angular momentum, which have been adopted for new quantum cryptographic protocols

Sönke Schmidt