The effect of the presence of two probe waveguides on the dynamics of hyper-Raman processes is studied in terms of quantum Zeno and anti-Zeno effects. Specifically, the enhancement (diminution) of the evolution of the hyper-Raman processes due to interaction with the probe waveguides via evanescent waves is viewed as quantum Zeno (anti-Zeno) effect. We considered the two probe waveguides interacting with only one of the optical modes at a time. For instance, as a specific scenario, it is considered that the two non-degenerate pump modes interact with each probe waveguide linearly while Stokes and anti-Stokes modes do not interact with the probes. Similarly, in another scenario, we assumed both the probe waveguides interact with Stokes (anti-Stokes) mode simultaneously. The present results show that quantum Zeno (anti-Zeno) effect is associated with phase-matching (mismatching). However, we did not find any relation between the presence of the quantum Zeno effect and antibunching in the bosonic modes present in the hyper-Raman processes.
Squeezing properties of degenerate high-order hyper-Raman lines emitted by a two-level system
非线性光学过程的量化描述可以从开发新的非经典光源的角度来考虑。作为一种特殊情况,它是有用的,以表征由经典驱动系统发出的光,因为在许多实际情况下的激励是激光束。作为物质模型,我们选择了一个两能级系统。在早期的工作中,我们研究了光子统计和模态间互相关物理Rev. A 104(3):033703,(2021),并注意到压缩主要存在于特定的参数集中,对应于超拉曼线的简并性。在这里,我们专注于这组特定的参数,呈现挤压的细节。
A Raman-Heterodyne Study of the Hyperfine Interaction of the Optically-Excited State $^5$D$_0$ of Eu$^{3+}$:Y$_2$SiO$_5$
在最近的工作中,在Y $_2$ SiO $_5$晶体中的位置1处取代钇的$^{151}$ Eu $^{3+}$的自旋相干时间已延长至6小时[ \textit{Nature} \textbf{517},177(2015)]。为了使这种长寿命的自旋相干性用于光量子存储器应用,我们使用拉曼外差检测的核磁共振实验表征了光激发态$^5$ D $_0$的超精细相互作用。根据在200个不同取向的磁场中获得的实验谱,拟合了激发态和基态的有效自旋哈密顿量。为了证明拟合参数的正确性和在量子存储协议中的潜在应用,我们还描述了基态超精细相互作用,并预测了产生6小时长的相干时间的临界磁场。得到了临界磁场下$^7$ F $_0$基态和$^5$ D $_0$激发态的完整能级结构。这些结果为量子存储协议的设计和光抽运策略的优化提供了理论依据,为实现长寿命光子量子存储器提供了理论依据。
The Raman dressed spin-1 spin-orbit coupled quantum gas
最近实现的自旋轨道耦合量子气体(Y. J Lin { \it等},Nature 471,83-86(2011); P. Wang { \it等人},PRL 109,095301(2012); L. W. Cheuk { \it et al}.,PRL 109,095302(2012))标志着冷原子社区的突破。在这些实验中,我们从超精细流形中选取了两个超精细态,用Raman修整的方法模拟了一个赝自旋1/2自旋轨道耦合系统,该方法适用于玻色子和费米子气体。在这项工作中,我们表明,在这些实验中使用的方法可以推广到创建任何大的赝自旋自旋-轨道耦合气体,如果更多的超精细态的拉曼激光器同等耦合。作为一个例子,我们详细地研究了一个三个超精细态的量子气体在喇曼激光作用下的耦合,发现当三个超精细态的能级位移相当时,在能带色散的底部会出现三重简并极小值,从而实现了一个自旋1自旋轨道耦合的量子气体.这三个最小制度的一个新的特点是,可以有两种不同的条纹相位具有不同的波长,这有一个有趣的连接到自旋1旋量BEC的铁磁和极性相没有自旋轨道耦合。