Generation of polarization-vector vortex mode hybrid entangled photon pairs from warm atoms

Vector vortex beams with varying polarization on the transversal profile can be used to increase information capacity and found applications in optical communication, optical trapping, high-resolution imaging, and quantum information. Here, we experimentally generate polarization-vector vortex mode hybrid entangled photon pairs in warm 85 Rb atomic vapor via spontaneous four-wave mixing (SFWM). Specifically, we firstly generate non-classical biphotons with high g (2) and then achieve polarization entanglement via coherent superposition of two SFWM paths by using beam displacers in a phase self-stabilized interferometer configuration. Finally, we realize polarization-vector vortex mode hybrid entanglement by utilizing q-plates, and a fidelity of 94.92% is obtained. This work may benefit the use of vector vortex beams in a quantum network based on atoms.