Spontaneous decay process of a two-level atom embedded in a one-dimensional structure containing left-handed material

The spontaneous decay process of a two-level atom embedded in a one-dimensional structure containing left-handed material (LHM) is investigated. We first consider the case of the atom being in front of a LHM layer mounted on a mirror, where it has been claimed that the atomic decay would be inhibited completely. Here we introduce dispersion and dissipation in the LHM, and find that there are two factors that weaken the inhibition of spontaneous decay. One is atomic nonradiative decay at shorter distances and the other is the instantaneous radiative decay process for larger distances. Then we discuss the decay process of an atom embedded in a one-dimensional photonic crystal composed of alternate LHM and ordinary material [right-handed material (RHM)] layers (LHM-RHM PC). Because of two special characteristics of the LHM, phase compensation and the fact that a frequency with negative index is usual near the material resonance frequency, both the radiative and nonradiative decay processes in the LHM-RHM PC are much different from those in a RHM PC. Under appropriate condition, the population evolution of atoms in a LHM-RHM PC displays oscillatory behavior.