首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  免费   8篇
物理学   8篇
  2015年   1篇
  2014年   1篇
  2012年   2篇
  2010年   2篇
  2008年   1篇
  2004年   1篇
排序方式: 共有8条查询结果,搜索用时 0 毫秒
1
1.
<正>We present a theoretical study of quantum coherent effects in a A-three-level system with a strong bichromatic coupling field and a weak probe field.When one component of the strong bichromatic coupling field is resonant with a corresponding transition and the other is detuning with an integer fraction of the Rabi frequency of the resonant field, the absorption spectrum exhibits a series of symmetrical doublets.While two frequencies of the strong bichromatic coupling field are symmetrically detuned from the transition,the position and the relative intensity of the absorption peak are both affected by the coupling field intensity and detuning.An explanation of the spectrum is given in term of the dressed-state formalism.  相似文献   
2.
杨丽君  马腾  孙克家  冯晓敏 《物理学报》2015,64(6):64205-064205
研究了外加微波场作用下三能级原子系统的无粒子数反转放大特性. 通过求解系统的密度矩阵方程得到其探测吸收谱. 结果表明, 介质对探测场的吸收呈现多峰结构, 并且在强微波驱动场的作用下, 特定范围内出现了明显的负吸收(即光放大). 进一步定量分析各能级粒子数布居随作用场强度的变化, 揭示出该三能级原子系统呈现无粒子数反转光放大的规律. 最后, 采用缀饰态理论对探测吸收特性做出了准确的解释.  相似文献   
3.
在通常的Λ型三能级系统中,光学耦合场和探测场分别激发两个不同的光学跃迁,探测吸收谱呈现电磁诱导透明(EIT)特性.若将此系统拓展为光学-射频双光子耦合场和探测场共同作用下的准Λ型四能级系统,探测吸收谱呈现电磁诱导吸收(EIA)和EIT两种特性.通过求解系统的密度矩阵方程,分析了EIA和EIT的产生条件,并给出了相应的缀饰态解释.研究结果表明,在准Λ型四能级系统中,光学耦合场对EIA和EIT的形成起决定作用,共振时出现EIA,非共振时出现EIT,而且EIA和EIT的线宽随着光学耦合场拉比频率的增大而增加. 关键词: 电磁诱导透明 电磁诱导吸收 射频场 光学耦合场  相似文献   
4.
The effect of the Bloch-Siegert shift on a strongly driven transition is studied in a three-level double-resonance configuration and the result is presented in this paper. We show that when a resonantly driven transition is probed to a third level, the Bloch-Siegert shift leads to an asymmetric Autler-Townes doublet. An important conclusion is that the asymmetry depends only on the driving field intensity, in contrast to a previous study where it is reported that the asymmetry depends not only on the driving field intensity but also on the characteristics of the three-level system. Our result implies an alternative way of measuring the Bloch-Siegert shift.  相似文献   
5.
采用时滞反馈的方法实现了对气体放电半唯象模型中时空斑图的控制.在Turing—Hopf切空间附近分析了时滞反馈对Turing模与Hopf模的影响,确定了反馈参数与系统振荡频率及临界波长的关系.结果表明,在保持外加电压不变的情况下,时滞反馈可有效控制斑图的转换.增加反馈强度或延迟时间等效于增加外加电压.进一步利用二维数值模拟进行了验证.研究结果对气体放电系统中实现斑图的控制提供了一种新思路.  相似文献   
6.
We analyze entanglement properties of entangled coherent state (ECS), |α,0) 1,2 +|0,α) 1,2, with and without photon losses. By separating the coherent state into ]a) = co|0) + √-Co2|α), we derive exact results of the logarithmic negativity EN, which quantifies the degree of entanglement between the two bosonic modes. Without particle losses, E~ = 1 for the NOON state; while for the ECS, E jr increases from 0 to 1 as |α|-→∞. In the presence of photon losses, we find that the ECS with large enough photon number is more robust than that of the NOON state. An optimal ECS is obtained by maximizing E~ with respect to l a 12.  相似文献   
7.
We present a theoretical study of quantum coherent effects in a λ-three-level system with a strong bichromatic coupling field and a weak probe field. When one component of the strong bichromatic coupling field is resonant with a corresponding transition and the other is detuning with an integer fraction of the Rabi frequency of the resonant field, the absorption spectrum exhibits a series of symmetrical doublets. While two frequencies of the strong bichromatic coupling field are symmetrically detuned from the transition, the position and the relative intensity of the absorption peak are both affected by the coupling field intensity and detuning. An explanation of the spectrum is given in term of the dressed-state formalism.  相似文献   
8.
李晓莉  张连水  孙江  冯晓敏 《物理学报》2012,61(4):44202-044202
本文通过建立Λ形四能级原子系统, 研究了微波驱动精细结构能级跃迁引起的电磁诱导负折射效应. 微波场作用于基态精细结构能级之间, 与不同精细结构能级之间的电偶极矩或磁偶极矩发生耦合, 使系统在某些频率处呈现负折射特性.同时, 两个耦合场各自激励一对基态和激发态之间的光学跃迁. 通过改变两个耦合场的频率失谐量控制负折射区域的频带宽度.结果表明, 耦合场失谐时出现负折射特性的频率范围比耦合场共振时迅速缩小, 而且耦合场负失谐和正失谐时的变化规律不同.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号