The Steady-state Entanglement Property Of Two-mode Cavity Field In A Three-level Atom Cavity-QED System

Since 1990s, information science , which mainly includes quantum computer and quan-tum communication, has evolved as a new research field. Quantum entangled states, as a fun-damental physical resource of quantum information processing, are extensively used in quan-tum computation and quantum communication, quantum teleportation, and quantum densecoding, etc. One of the key problem is the generation, measurement and manipulation ofquantum entangled states in quantum systems.Now, continuous variable entanglement has attracted a lot of attention in quantum opticsand quantum information due to the experimental realization of quantum information process-ings in continuous variable regime. Any attempt to exploit the entanglement have to, however,face the corruption of the entanglement by unavoidable decoherence. As a result, how toproduce the robust, steady, and high entanglement is an interesting research issue.The main content of this paper is theoretically to study the steady-state entanglementproperty and the total average photon number of two-mode cavity field in a single atom cavity-QED system under the presence of cavity losses. Specifically, the main work of our paperconsists of the following sections:(1) The first part is exordium, we introduce the quantum entanglement and the applicationof the quantum entanglement in quantum communication.(2) In the second part, we introduce the determinant and measurement of the quantumentanglement, especially several usual methods to determine and measure entanglement.(3) In the third part, we take two-level atom and three-level atom as examples to introducethe interaction theory of the cavity fields with atomic medium, especially the expression ofHamilton.(4) In the last part, we research the steady-state entanglement property and total averagephoton number of two-mode cavity field in a single atom cavity-QED system. We also analyze and discuss the in?uence of parameters, such as frequency detuning and intensity ofthe classical fields, on the steady-state entanglement property of cavity field. Our investigativeresults show that the steady-state entanglement of cavity field can be realized over a widerange of the system parameters, based on our scheme. We can manipulate the degree of theentanglement and the total average photon number of two-mode cavity field by changing theclassical fields.