Entanglement Dynamics Of Three-Qubits In1-D Photonic Crystals

In this paper, we study the entanglement dynamics of three qubits X-states embedded in one-dimensional(1D) photonic crystals. The properties like isotropic of one-dimensional(1D) photonic crystals make it widely used in researches and some application fields. We set the three qubits initially in X-states, because this kind of states have the characteristic of maintaining X-type during evolution. It simplified the calculation process during investigation. Our model is placing three identical two level atoms separately in three identical one-dimensional photonic crystals. In photonic crystals, the qubit is coupled together with a radiation field. Due to the difference of the density of state in the band gap or band edge of photonic crystals, there must be some influence on the spontaneous emission of atoms which leads to the changing of three qubits entanglement. We utilize negativity measures to quantify entanglement. In this paper, we explore the qubits prepared in different initial states. The results show that entanglement is restricted by the initial coherence, the population in the excited state, the detuning and the symmetry of qubits.