Quantum Effects of Bose-Einstein Condensates

In this paper,we study quadrature squeezings of two Bose-Einstein condensates with collision and non-classical properties of pair entanglement in four wave mixing in Bose-Einstein condensates.With the aid of a numericalmethod,we find that the two modes(pair entanglement modes)αand αmay exhibit quadrature squeezing,in whichthey are affected by the initial phase.It is shown that the two pump modes exhibit the same super-Poissonian distri-bution.The analysis for the mode-mode correlation shows that there always exists a violation of the Cauchy-Schwartzinequality,which means that correlation between the two pump modes is nonclassical.