Spontaneous emission by two atoms with different resonance frequencies near a metal surface. II

王德华

K. C. Liu, Thomas F. George

The interaction between electromagnetic radiation and two two-level atoms with different resonance frequencies near a perfectly conducting metal surface is considered. The atom-atom and atom-surface separations are assumed to be smaller than the corresponding mean resonance wavelength. A quantum-mechanical version of the image method is adopted to study the spontaneous emission by such an atomic pair. Within the framework of this approach, each individual atom and its corresponding image are kinematically correlated, while dynamically they are in effect independent. The total radiation rate of the atomic system is calculated as a function of time for various values of frequency difference. Explicit results are given for several different initial states of the atomic system. Some of them exhibit superradiance, and some initially act as photon-trapping states and eventually are able to undergo radiative decay. Oscillations as a manifestation of beating appear in the time evolution of the radiation rate in all cases of the various initial states, when the frequency difference becomes larger than a critical value given as twice the mean halfwidth of the atomic resonance lines.

Akiyoshi Takada, Kikuo Ujihara

Vassilios Yannopapas, Emmanuel Paspalakis, Nikolay V. Vitanov

We show that the quantum interference between two spontaneous emission channels can be greatly enhanced when a three-level V-type atom is placed near plasmonic nanostructures such as metallic slabs, nanospheres, or periodic arrays of metal-coated spheres. The spontaneous emission rate is calculated by a rigorous first-principles electromagnetic Green's tensor technique. The enhancement of quantum interference is attributed to the strong dependence of the spontaneous emission rate on the orientation of an atomic dipole relative to the surface of the nanostructure at the excitation frequencies of surface plasmons.

海珍 趙

Xiao-shen Li, Chang-De Gong

Spontaneous-emission properties and resonance fluorescence for a two-level adatom near the surface of a semi-infinite superlattice with quasiperiodic structure are studied by use of surface-dressed optical Bloch equations and Maxwell's equations. Effects of dielectric properties and the geometric structure of this superlattice on spontaneous-decay rate and frequency shift, resonance-fluorescence spectrum, time evolution of adatomic inversion, and fluctuations of the dipole moment for this adatom are discussed and some novel phenomena are discovered.