Theory of Spontaneous-Emission Line Shape in an Ideal Cavity
Theory of Spontaneous-Emission Line Shape in an Ideal Cavity
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DOI：
10.1103/physrevlett.51.550
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发表时间：
1983-08
影响因子：
8.6
通讯作者：
J. Sánchez-Mondragón;N. Narozhny;J. Eberly
中科院分区：
文献类型：
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作者：
J. Sánchez-Mondragón;N. Narozhny;J. Eberly
单个原子是研究物质和辐射相互作用的理想“实验室”。这些相互作用中最基本的量子力学是自发发射的原因。自由空间中自发辐射的性质是众所周知的，但如果辐射原子被封闭在空腔中，情况就不是这样了。“最近克莱普纳”提出了一个远离共振的微波空腔实验。他强调了极大地抑制比德堡原子自发发射率的可能性，该原子的首选（也是微波）跃迁频率落在腔模密度远低于自由空间态密度的光谱区域。自然线宽大大减少是一个预期的结果。人们普遍认识到，从未给出理想化腔条件下自然线宽的完全量子力学理论。我们将在下面提到其主要原因。在这封信中，据我们所知，我们提出了关于具有孤立跃迁频率的原子自发发射到无损腔中的光谱的第一个完全量子力学预测。原子跃迁频率可以任意接近或远离单个类似隔离的空腔谐振线许多线宽。我们不仅证明量子理论做出了与相应的半经典（非量子化电磁场）理论截然不同的预测，
A single atom is an ideal" laboratory" in which to study the interactions of matter and radiation. The most fundamentally quantum mechanical of these intereactions is responsible for spontaneous emission. The nature of spontaneous radiation in free space is well known, but this is not the case if the radiating atom is enclosed in a cavity.'Recently Kleppner'has proposed a microwave cavity experiment very far from resonance. He has emphasized the possibility of greatly sup-pressing thespontaneous emission rate of a Bydberg atomwhose preferred (also microwave) transition frequency falls in a spectral region where the cavity mode density is much lower than the free-space density of states. Greatly de-creased natural linewidths are one expected con-sequence.It is not generally realized that a fully quantum mechanical theory of natural linewidth under idealized cavity conditions has never been given. We will mention below theprincipal reasons for this. In this Letter we present what, to the best of our knowledge, are the first fully quantum mechanical predictions about the spectrum of spontaneous emission into a lossless cavity, by an atom with an isolated transition frequency. The atomic transition frequency may be arbitrar-ily near to, or many linewidths away from, a single, similarly isolated, cavity resonance line. We show not only that quantum theory makes strikingly different predictions from the corre-sponding semiclassical (nonquantized electro-magnetic field) theory,