排序方式: 共有3条查询结果,搜索用时 31 毫秒
1
1.
2.
研究了束缚在梯子形光晶格中的中性原子与高精度腔耦合的系统,发现由超辐射引起的准周期调制可以导致迁移率边和重返局域化现象的出现.在平均场近似下,超辐射现象可以引起两种不同频率的准周期调制,它们可以由腔场和泵浦场有效调节.在本文的观测范围内,当高频调制强度小于某一临界值时,系统随着低频调制强度的增加经历一次局域转变.通过数值求解分形维度、密度分布、平均参与率、平均逆参与率以及标度分析,证明了局域转变历经的临界相区存在迁移率边;当高频调制强度大于临界值时,随着低频调制强度的增强,系统依次经历完全扩展相-临界相-完全局域相-临界相-完全局域相,这是一个典型的重返局域化现象.最后给出了局域化相图.该研究结果为超辐射相变和重返局域化现象的研究建立了联系,也为重返局域化的研究搭建了新的平台. 相似文献
3.
We investigate the dynamics of parity-and time-reversal(PT) symmetric two-energy-level atoms in the presence of two optical and one radio-frequency fields. The strength and relative phase of fields can drive the system from the unbroken to the broken PT symmetric regions. Compared with the Hermitian model, Rabi-type oscillation is still observed, and the oscillation characteristics are also adjusted by the strength and relative phase in the region of the unbroken symmetry. At the exception point, the oscillation breaks down. To better understand the underlying properties we study the effective Bloch dynamics and find that the emergence of the PT components of the fixed points is the feature of the PT symmetry breaking and the projections in the x–y plane can be controlled with high flexibility compared with the standard two-level system with the PT symmetry. It helps to study the dynamic behavior of the complex PT symmetric model. 相似文献
1