Entangled quantum states of atomic systems

Willi-Hans Steeb, Yorick Hardy

Jiaojiao Chen, Baolong Fang, Wei Xiong

Abstract Quantum entanglement is important quanum resources in quantum information sicence. Here we propose an approach to preparing atomic quantum entanglement in a hybrid atom-cavity-fiber system. Using quantum Zeno dynamics method, the system evolution states are always split into a series of Zeno invariant subspaces consisting of dark and bright states. By choosing the initial state of the system, the bright states are all neglected and only dark states are kept to build the effective Hamiltonian. By tuning the system parameters, two-atom multiple-dimensional entanglement, two-atom Bell state, and three-atom GHZ state can be realized by one step. Our proposal provides a way to perform quantum information processing with dark states.

Jānis Ruža

Chao-Qian Pang, Mai-Lin Liang

A scheme is presented to generate an entangled atomic state, for which the quantum phase aects the atom atom entanglement when the atom interacts with external light elds.The quantum phase enhances the entanglement and extends the time that the system stays in stronger entanglement state or the phase makes the system more robust.It is also shown that the quantum phase is able to delay the entanglement sudden death and hasten the entanglement revival.

V. M. Akulin

Yang Zhi-yong

A physical system which consists of the multimode cavity fields and the coupling atoms was proposed.In this system,a novel way of translating quantum entangled information has been discovered.The atoms can get the quantum entangled information stored in the entangled state of the cavity field when the atoms,which all are initially in ground state,cross the cavities with a controlled speed.And the atoms can release the quantum entangled information into the vacuum state cavities when the entangled state atoms cross the cavities.By this means,one can realize the entangled information exchange between cavities and atoms.The quantum entangled information transferring between two sets cavities was also discussed using the atomic properties which the atoms can pick up and release quantum entangled information. Besides,the quantum information can be preserved under the different time conditions.