Two-qubit entanglement dynamics for two different non-Markovian environments

We study the time behaviour of entanglement between two noninteracting qubits, each immersed in its own environment for two different non-Markovian conditions: a high-Q cavity slightly off-resonant with the qubit transition frequency and a nonperfect photonic band gap ( PBG). We find that revivals and retardation of entanglement loss may occur by adjusting the cavity-qubit detuning, in the first case, while partial entanglement trapping occurs in a nonideal PBG.