薛定谔猫态光场与二能级原子相互作用系统的量子特性

在非旋波近似下,通过采用相干态正交化展开的方法,研究了薛定谔猫态光场与二能级原子相互作用系统中,原子的布局数和光场的反聚束效应,并与旋波近似下的结果进行了对比.在旋波近似与非旋波近似下,讨论了初始光场强度、相干态间的相位角以及失谐量对原子布局数和光场反聚束效应的影响;在非旋波近似下,讨论了强弱耦合情况下光场的反聚束效应.研究结果表明:旋波近似与非旋波近似下,原子的布局数随着初始光场强度的不同,表现出不同的特性;当初始光场强度较小时,旋波近似与非旋波近似下,原子的布局数表现出相同的特性;随着初始光场强度的增大,旋波近似下,原子的布局数将表现出坍塌现象.耦合强度较大时,光场的聚束与反聚束效应在非旋波近似与旋波近似下有较大的区别;非旋波近似下,随着初始光场强度的增大,光场一直处于聚束效应状态;而旋波近似下,光场的聚束效应与反聚束效应交替出现.

Quantum properties in a system interacting a two-level atom with the Schrödinger cat state

Applying the method of coherent states orthogonalization expansion, the atomic population and the antibunching effect of the light field are studied in the system of interaction between a two-level atom and the Schrödinger cat state without rotating wave approximation (RWA). The results are compared with those in RWA. The influences of the original strength of the light field and two coherent phase angles on the atomic population and antibunching effect with RWA and without RWA are discussed respectively, and the antibunching effect in the weak coupling condition is also discussed without RWA. The results show that the atomic populations with RWA and without RWA have different properties with the different original strengths of the light field. As the original strength of the light field is smaller, the atomic populations with RWA and without RWA show the same properties, but with the increase of the original strength of the light field the population with RWA will show the collapse phenomenon. When the coupling strength is larger, the antibunching effects with RWA and without RWA have bigger difference. Without RWA the light field will appear bunching effect, whereas with RWA it will appear alternately the bunching effect and the antibunching effect with the increase of the original strength of light field.