Entanglement Of Dressed-atom And Field Via Four-wave Mixing

Using four-wave mixing process to produce continuous variable entanglement is an important research topic in quantum optics. It is widely used in quantum information and quantum networks, etc. In this work, the entanglement properties of dressed-atoms and two-mode cavity fields are discussed in the system of four-wave mixing, which is embedded in a two-mode cavity. Finally, we obtained the following results via solving Heisenberg-Langevin equations which evolved from master equation:First, the greater the ratio of atomic relaxation time and cavity field relaxation time are, the greater the entanglement of dressed-atomic and cavity fields are. In the case of non-adiabatic elimination, the cavity fields arrive at steady state before the atoms when the atomic relaxation time is greater than the cavity relaxation time. Owing to the memory effect of the atoms, the fluctuation are appropriately compressed, then the entanglement of the dressed-atoms and the cavity fields.Second, the he entanglement of dressed-atoms and cavity fields enhance, when the mistuning between the atoms and the driving field reduce. When atoms and driving field are near resonance, the connections strengthen between atoms and the cavity fields. When the atoms and driving fields are on resonance, the population difference of dressed-atoms become zero, so the entanglement of the dressed-atoms and cavity fields disappears.Third, the entanglement interval of dressed-atoms and the cavity fields widen when the driving field Rabi frequency increase. Increasing the driving field Rabi frequency, entanglement of the dressed-atoms and the cavity field will not change, but the entangled interval widen.Fourth, along with the increase of working parameters, the entanglement of dressed-atoms and the cavity fields strengthen. When the working parameters increase, the degree of coupling between atoms and the cavity fields increase, at the same time, the rate of decay decreases and the connections between dressed-atoms and the cavity field enhance.