宏观场与环境作用过程中的纠缠突然死亡与突然产生

Sudden birth versus sudden death of entanglement during the interaction of macroscopic fields with environments

研究了两个初始处于纠缠相干态上的宏观场各自独立地与一个环境相互作用的系统,环境对腔场的影响只体现在腔场光子数的泄漏上.采用共生纠缠(concurrence)度量两个宏观场间的纠缠,并给出宏观场纠缠的解析解,以分析这种系统中宏观场纠缠的动力学特性.研究表明当场的初始平均光子数较大时,即使很小的光子泄漏率也会导致腔场间出现纠缠突然死亡现象.同时研究结果也表明光子从腔场泄漏到环境后会导致两环境间的纠缠突然产生,而这种纠缠产生的时机直接与腔场的初始光子数相关.本文还进一步发现在大光子数的情况下,在任何时刻任意一个腔场与任意一个环境间都不会产生纠缠.

Decoherence of two initially entangled macroscopic fields each interacting with a loss environment is investigated;environment only have an effect on the leakage of field’s photons. The cavity-cavity entanglement is characterized by concurrence. The results obtained by resolvable values show a surprising result： the two entangled macroscopic fields become completely disentangled even though the leakage rate of the cavities fields is very tiny. Then we find that when the cavity entanglement disappears, the environment entanglement appears. Finally, we present an explanatory study of other entanglement partitions.