  The decoherence of two initially entangled qubits in anisotropic band gap
photonic crystal has been studied analytically without Born or Markovian
approximation. It is shown that the decoherence dynamics of two qubits in
photonic crystal is greatly different from that of two qubits in vacuum or
subjected to usual non-Markovian reservoir. The results also show that the
finite time decoherence invoked by spontaneous emission could be suppressed
efficiently and the entanglement of the Bell state possesses odd parity is more
easily preserved in photonic crystal than that of the Bell state possesses even
parity under the same condition. A store scheme for entangled particle pair is
proposed.
