Spontaneous emission from a three-level atom embedded in anisotropic photonic band gap structures

Abstract

Abstract We investigate spontaneous emissions from a three-level atom embedded in realistic anisotropic photonic band gap structures, where the band edge is assumed to be midway between the two upper levels of the atom. In the anisotropic model, the atom-field interaction is reduced to be smaller than that in the ideal isotropic model, which results in the reduction of suppression and oscillation effects in the spontaneous emission; however, we demonstrate that the suppression is strongly enhanced even in the anisotropic model by expanding the detuning between the upper level and the band edge, while the oscillation is greatly reduced. This demonstration is carried out by calculating the atomic state vector for a wide range of the detuning. Using the state vector, the atom-field interaction is studied for two field parts, a localized part and a propagating part, separately. For the localized part, the atom-field interaction is enhanced by expanding the detuning, in spite of the anisotropy, which leads to a strong suppression effect, while for the propagating part, the atom-field interaction is reduced, which leads to a weak oscillation effect. This result is relevant to strong memory effects with high-speed switching, which are attractive properties for a qubit.