两量子比特耦合到共同环境系统中纠缠演化特性的研究

Study of entanglement dynamics of two qubits coupled to a common environment system

通过计算线性熵研究了两量子比特耦合到共同环境系统中纠缠演化特性,讨论了量子比特与环境的相对耦合强度以及两量子比特初始纠缠度对纠缠的影响。结果表明量子比特处于好腔时,线性熵随时间演化呈振荡行为,量子比特和环境的相对耦合强度越大,线性熵稳态值越大;量子比特处于坏腔时,两量子比特与环境之间纠缠产生的阈值时间与两量子比特初始纠缠度无关。

The entanglement dynamics of two qubits coupled to a common environment system is investigated by computing the linear entropy. The effect of the relative coupling strength of the qubit with environment and the initial entanglement degree of two qubits are discussed. The results show that the linear entropy shows oscillatory behaviour as time evolves when the qubits are in the good-cavity. The steady value of the linear entropy becomes larger as the relative coupling strength of the qubit with environment increases. When the qubits are in bad-cavity,the threshold time for the creation of the entanglement between two qubits and environment is independent of the initial entanglement degree of two qubits.