两体二能级系统的纠缠特性

Entanglement Properties of Bipartite Two-level System

通过研究与外界环境相互作用的两体二能级系统的动力学演化,分析了两体二能级系统任意初始态的约化密度矩阵。并用类Werner态计算了初始态的约化密度矩阵。进一步通过Concurrence的表达式定量地分析了两体二能级系统的纠缠度在零温玻色欧姆和零温玻色超欧姆环境下随参数t,r,p的变化规律。最后得出:在相同条件下,零温玻色超欧姆环境下的纠缠突然死亡时间要比零温玻色欧姆环境下的纠缠突然死亡时间长。

By studying the dynamical evolution of the bipartite two-level system which interacts with external environment, we analyze the reduced density matrix for an arbitrary initial state of the bipartite two-level system. Moreover, we calculate the initial state reduced density matrix with Werner-like state. Further, we analyze quantitatively variation law of entanglement of the bipartite two-level system with the expression of Concurrence in the bosonic ohmic and bosonic supraohmic environment at zero temperature as the parameters t, r and p change. Finally, we conclude that in the same condition, entanglement sudden death time under the bosonic supraohmic environment at zero temperature is more than that under the hosonic ohmic environment at zero temperature.