Considering two two-level atoms initially in the entanglement state,one atom of two atoms is put into initially Fock state light cavity and has resonant interaction.The entanglement evolution between atom in cavity and light field is investigated.Negativity is used to quantify the degree of entanglement.Through comparing the results if direct selective measurement is performed or not,the influences of state-selective measurement of the atom outside the cavity on the entanglement properties of between atom inside cavity and field are discussed.The results obtained using the numerical method show that the entanglement between atom inside cavity and light field is strengthened through the state-selective measurement of the atom outside the cavity.
Considering two Λ-type three-level atoms initially in the entangled state, one atom is poured into the cavity and interacts with a two-mode cavity. The squeezing and antibunching effects of the field are investigated. The influences of the selective atomic measurement and the intensity of the coherent field, which interacts with atom on squeezing and antibunching effect of the field, are discussed. The results obtained by numerical calculations show that squeezing and antibunching effect of the field can be strengthened through selective atomic measurement for atom outside of the cavity.
In this paper,nonclassical effects of quantum lightfield interacting with Bose- Einstien condensate (BEC) are investigated when the quantum lightfield is initially in a coherentstate and the atomic field of the BEC is initially in a number state.It is shown that the quantum light field exhibits sub- Poinssonian photon statistics in the time evolution butthere is no second- order squeezing of the quadrture components of the light field in the wholedynamic evolution.Itisfound thatundersuitable conditions,thehight- ordersqueezing of the lightfield can occur.Concretely ,the fourth order squeezing of the lightfield iis studied in detail.