Generating quantum correlated twin beams by four-wave mixing in hot cesium vapor

摘要

Using a nondegenerate four-wave mixing process based on a double-$\Lambda$scheme in hot cesium vapor, we generate quantum correlated twin beams with amaximum intensity-difference squeezing of 6.5 dB. The substantially improvedsqueezing can be mainly attributed to very good frequency and phase-differencestability between the pump and probe beams in our experiment.Intensity-difference squeezing can be observed within a wide experimentalparameter range, which guarantees its robust generation. Since this schemeproduces multi-spatial-mode twin beams at the Cs $D_{1}$ line, it is ofinterest for experiments involving quantum imaging and coherent interfacesbetween atomic and solid-state systems.