Disentanglement and Decoherence in the Three-qubit System
三量子位系统的消相干和退纠缠

The disentanglement and decoherence in the three-qubit system are studied based on the model of reservoir of harmonic oscillators by solving the non-Markovian approximation master equation, in which they are caused by a pure dephasing process. The GHZ-class state, W-class state and WGHZ-class state are discussed in detail. In all cases, the time scales of the decoherence and disentanglement are obtained. For the initial GHZ-class state, the coherence and entanglement decay completely; for the initial W-class state, the decoherence and disentanglement do not occur; for the initial WGHZ-class state, the decoherence happens partly, and the entanglement varies with time firstly and then becomes a certain asymptotic value.