Super- and subradiance of clock atoms in multimode optical waveguides
Super- and subradiance of clock atoms in multimode optical waveguides
复制标题
多模光波导中时钟原子的超辐射度和亚辐射度
DOI：
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发表时间：
2018
影响因子：
3.3
通讯作者：
H. Ritsch
中科院分区：
文献类型：
--
作者：
L. Ostermann;C. Meignant;C. Genes;H. Ritsch
光纤的横向受限传播模式在放置在其场中的原子之间介导几乎无限范围的能量交换，这增加了固有的自由空间偶极-偶极耦合。通常，单原子自由空间衰减速率大大超过进入引导光纤模式的发射速率。然而，按比例增加的原子数以及系统的大小相当于进入集体发射制度，光纤诱导的超辐射自发辐射占主导地位的自由空间衰减。我们数值研究了这种超辐射和亚辐射衰变的高激发原子态的一个或几个横向光纤模式，目前在空芯光纤。作为特定的激发场景，我们将完全反转状态的衰减与标准拉姆齐或拉比干涉测量法中横向或沿着光纤轴施加π/2脉冲的情况进行比较。虽然平均场方法不能正确描述超辐射的起始，但考虑成对原子-原子量子关联的二阶近似一般证明足以可靠地描述从两个到几百个粒子的集合的超辐射。相比之下，子辐射的完整解释需要包含所有高阶量子关联。考虑多个导模引入了一个自然的有效截止的相互作用范围出现从不同的光纤贡献的相移。
The transversely confined propagating modes of an optical fiber mediate virtually infinite range energy exchanges among atoms placed within their field, which adds to the inherent free space dipole–dipole coupling. Typically, the single atom free space decay rate largely surpasses the emission rate into the guided fiber modes. However, scaling up the atom number as well as the system size amounts to entering a collective emission regime, where fiber-induced superradiant spontaneous emission dominates over free space decay. We numerically study this super- and subradiant decay of highly excited atomic states for one or several transverse fiber modes as present in hollow core fibers. As particular excitation scenarios we compare the decay of a totally inverted state to the case of π/2 pulses applied transversely or along the fiber axis as in standard Ramsey or Rabi interferometry. While a mean field approach fails to correctly describe the initiation of superradiance, a second-order approximation accounting for pairwise atom–atom quantum correlations generally proves sufficient to reliably describe superradiance of ensembles from two to a few hundred particles. In contrast, a full account of subradiance requires the inclusion of all higher order quantum correlations. Considering multiple guided modes introduces a natural effective cut-off for the interaction range emerging from the dephasing of different fiber contributions.
影响因子：
3.3
作者：
Falke, Stephan;Lemke, Nathan;Lisdat, Christian
通讯作者：
Lisdat, Christian