Entangled images: generation and delay with four-wave mixing - Alberto Marino

I will present experimental studies that we have carried out on the generation and delay of highly entangled beams of light, know as twin beams. The quantum correlations present in twin beams have recently generated great interest due to their applications in quantum information, quantum imaging, and quantum computing. In the first part of the talk I will show that non-degenerate four-wave mixing (4WM) in a rubidium vapor cell is an excellent source of continuous-variable (CV) entangled twin beams, with an intensity-difference noise of less than 13% of the classical shot-noise level. Unlike other systems that rely on the use of a cavity, the system that we use can support a large number of spatial modes. This leads to spatial quantum correlations and makes it possible to produce CV entangled images. In the second part I will show that, in addition to generating entangled twin beams, the 4WM process in a vapor cell can act as a tunable delay line for CV entanglement without significant degradation. This has allowed us to delay entangled images.