Generation of multiparticle three-dimensional entanglement state via adiabatic passage

A scheme is proposed for generating a multiparticle three-dimensional entangled state by appropriately adiabatic evolutions, where atoms are respectively trapped in separated cavities so that individual addressing is needless. In the ideal case, losses due to the spontaneous transition of an atom and the excitation of photons are efficiently suppressed since atoms are all in ground states and the fields remain in a vacuum state. Compared with the previous proposals, the present scheme reduces its required operation time via simultaneously controlling four classical fields. This advantage would become even more obvious as the number of atoms increases. The experimental feasibility is also discussed. The successful preparation of a high-dimensional multiparticle entangled state among distant atoms provides better prospects for quantum communication and distributed quantum computation.     

Implementation of quantum controlled phase gate and preparation of multiparticle entanglement in cavity QED

Schemes are presented for realizing quantum controlled phase gate and preparing an N-qubit W-like state, which are based on the large-detuned interaction among three-state atoms, dual-mode cavity and a classical pulse. In particular, a class of W states that can be used for perfect teleportation and superdense coding is generated by only one step. Compared with the previous schemes, cavity decay is largely suppressed because the cavity is only virtually excited and always in the vacuum state and the atomic spontaneous emission is strongly restrained due to a large atom-field detuning.     

利用偶极封锁制备多粒子三维纠缠态

选择碱金属原子的三个稳定基态为qutrit,其里德堡态为辅助态,借助调节经典脉冲所实现的单量子比特操作和偶极封锁机制分别制备了两原子三维最大纠缠态和三原子三维最大纠缠态。