Preparation of entangled states of four remote atomic qubits in decoherence-free subspace

Transfer and teleportation of quantum states encoded in decoherence-free subspace

“…Hk, 42.50.Dv Quantum state transfer and teleportation are significant components in quantum information processing, especially for quantum network. As the confined atoms in cavity QED system are well suited for storing qubits in long-lived internal states, spatially separated cavities could be used to build a quantum network assisted by photons [1,2,3,4,5,6,7,11]. On the other hand, decoherence due to the inevitable interaction with environment destroys quantum coherence.…”

“…So our scheme could not only protect quantum information from some decoherence, but also reduce the experimental difficulty compared to the previous schemes [1,4,5,11]. Furthermore, in our scheme, each node of the quantum network in DFS has individual input port for photons to complete necessary operations, and different operational results can be distinguished by * Electronic address: huawei.hw@gmail.com † Electronic address: mangfeng1968@yahoo.com detecting output photons.The main idea using cavity-assisted photon scattering to realize a controlled phase flip (CPF) between two atoms [3,4,5,6,11], is sketched below. Suppose that two identical atoms, each of which has a three-level configuration, are well located in a high-finesse cavity.…”

“…The main idea using cavity-assisted photon scattering to realize a controlled phase flip (CPF) between two atoms [3,4,5,6,11], is sketched below. Suppose that two identical atoms, each of which has a three-level configuration, are well located in a high-finesse cavity.…”

“…NOT whose function is to flip the logic-qubit | 0 ↔ | 1 [6], and thereby the state becomes (1/ √ 2)(|h | 0 + |v | 1 ) after the photon pulse comes back from the cavity i and the PBS. (2) Reflected by TR2, the photon pulse goes through HWP1, yielding the state (1/ √ 2)(|v | 0 +|h | 1 ).…”

Efficient spin Bell states and Greenberger–Horne–Zeilinger states analysis in the quantum dot–microcavity coupled system

“…Especially, the GHZ states [20], which can provide possibilities to test quantum mechanics against local hidden theory without inequality [19], is one of the most important resource in QIP. Till now, due to the large information capacity, great interest has arisen regarding the significant role of GHZ states in the foundations of quantum mechanics measurement theory and quantum communication [23][24][25][26][27][28][29]. Contrary to bipartite entangled states, GHZ states exhibit a special kind of entanglement between N ≥ 3 parties, providing a possibility to test quantum nonlocality in a one-shot manner.…”