Team

Cold rubidium and twisted light (TWIST)

Scientific activity

Quantum physics of the interaction between atoms and optical vortices.

The optical vortex – or twisted light – has the particularity of carrying a photonic orbital angular momentum (OAM), which is a quantity quantized by a relative integer. OAM provides a large bit-space for coding information. We also know how to superimpose OAMs and make them interact with matter.

As far as atoms are concerned, non-linear interactions are used and favored, enabling memory effects or the construction of OAM entanglement in emitted photon pairs.

Experiments to analyze the interaction between atoms and vortices are carried out on rubidium in a cell or cooled by laser, to which exciter laser beams previously shaped in phase by SLM (Spatial Light Modulator) are applied to confer an OAM or a superposition of OAMs.