Preparation of Non-Maximally Entangled States in the Atom-Cavity Systems

Shi‐Biao Zheng

Emilio H. S. Sousa, José Antonio Roversi

We propose a dissipative scheme to prepare maximally entangled steady states in cavity QED setup, consisting of two two-level atoms interacting with the two counter-propagating whispering-gallery modes (WGMs) of a microtoroidal resonator. Using spontaneous emission and cavity decay as the dissipative quantum dynamical source, we show that the steady state of this system can be steered into a two-atom single state as well as into a two-mode single state. We probed the compound system with weak field coupled to the system via a tapered fiber waveguide, finding it is possible to determine whether the two atoms or two modes are driven to a maximally entangled state. Through the transmission and reflection measurements, without disturbing the atomic state, when the cavity modes are being driven, or without disturbing the cavity field state, when a single atom being driven, one can get the information about the maximal entanglement. We also investigated for both subsystem, two-atom and two-mode states, the entanglement generation and under what conditions one can transfer entanglement from one subsystem to the other. Our scheme can be selectively used to prepare both maximally entangled atomic state as well as maximally entangled cavity-modes state, providing an efficient method for quantum information processing.

Jin Xing-Ri

We propose a scheme to prepare a maximally entangled state of two ladder-type three-level atoms with have difference coupling constant with a non-resonant thermal cavity and driven by the external strong classical flied. Because of the external driven strong classical flied, the photon-number-dependent parts in the effective Hamiltonian are canceled. The advantage of scheme is that the cavity may be in any state.

Nan Xu

Yh, Guo, Guiyun +1 more

Xin Jun-li

For the sake of making this kind of useful quantum information resource of quantum entanglement.Here we propose a new prepare process on the foundation of the cavity quantum electrodynamics technique project of the resonance interaction,put forward a kind of making process that atom entangled state.Made to prepare two typical quantum entangled states in cavity QED: GHZ and W states of atoms,which belong to inequivalent classes of entangled states.GHZ state is maximally entangled state,while W states are non-maximally entangled states.They hold many interesting applications in quantum information processing and high-precision measurements.Therefore it is expected to be implemented with the current cavity QED experimental technology.