Ultrafast modification of the spontaneous decay rate by plasmonic nanostructures: a step toward manipulation of a single atom

A controllable method for modifying spontaneous emission of an electric dipole located in close proximity to a plasmonic nanostructure is proposed. The nanostructure constructed of two triangular nanowires, in the form of a dimer, on a substrate in which the gallium film on the micrometer scale is the main layer. The results illustrate that phase transition of the gallium film from the alpha-crystalline to liquid phase leads to variation of the spectrum of radiative and nonradiative decay rates of the dipole where such a transition depends on parameters of the dipole, e.g. position, orientation and emission wavelength as well as on the nanostructure, e.g. shape and size of the dimer and also properties of the substrate. On the other hand, it is found that during phase transition modification of nanostructure resonances is negligible while the radiative decay rate changes.