THEORY OF THE CONTRIBUTION OF EXCITONS TO THE COMPLEX DIELECTIC CONSTANT OF CRYSTALS
THEORY OF THE CONTRIBUTION OF EXCITONS TO THE COMPLEX DIELECTIC CONSTANT OF CRYSTALS
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DOI：
10.1103/physrev.112.1555
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发表时间：
1958-01-01
期刊：
影响因子：
--
通讯作者：
HOPFIELD, JJ
中科院分区：
文献类型：
--
作者：
HOPFIELD, JJ
它表明，普通的半经典理论的光的激子态的吸收是不完全令人满意的（在相反的情况下，由于带间跃迁的吸收）。一个更完整的理论被开发出来。结果表明，激子是近似玻色子，在与电磁场的相互作用中，激子场起着经典极化场的作用。晶体与辐射场系统的本征态是光子与激子的混合态。激发的普通单量子光学寿命是无限的。只有在引入”三体”过程时才会发生吸收。该理论包括“局部场”效应，导致洛伦兹局部场校正时，它是适用的。导出了用积分吸收常数表示的振子强度的Smakula方程。
It is shown that the ordinary semiclassical theory of the absorption of light by exciton states is not completely satisfactory (in contrast to the case of absorption due to interband transitions). A more complete theory is developed. It is shown that excitons are approximate bosons, and, in interaction with the electromagnetic field, the exciton field plays the role of the classical polarization field. The eigenstates of the system of crystal and radiation field are mixtures of photons and excitons. The ordinary one-quantum optical lifetime of an excitation is infinite. Absorption occurs only when" three-body" processes are introduced. The theory includes" local field" effects, leading to the Lorentz local field correction when it is applicable. A Smakula equation for the oscillator strength in terms of the integrated absorption constant is derived.