四能级原子自发辐射的量子相干特性

The Coherence Properties of Spontaneous Radiation in the Four-level Atom

研究四能级原子的自发辐射。原子激发态是不稳定的,其必然会自发地向低能级衰变,产生自发辐射现象。本文针对四能级原子仅存在自发辐射的情况,基于量子力学和Kraus算子理论,利用约化密度矩阵方法,得到四能级原子自发辐射的密度矩阵元演化规律,从而分析量子态相干特性。

The spontaneous radiation of the four-level atom is studied. Atom＇s motivated state in not stable, it inevitably disintegrate into the lower energy state, which makes the phenomenon of the spontaneous radiation. On the basis of theories of quantum mechanics and Kraus operator, utilizing the reducible density rectangular method, the paper probes into the transformation of density matrix of the four-level atom which only in the case of the spontaneous radiation. The coherence properties of quantum states are analyzed.