Spontaneous decay of a two-level atom near the left-handed slab

Abstract

Spontaneous decay of a two-level atom near the left-handed material (LHM) slab is investigated. The contributions of the guided modes and the surface-plasmon polariton (SPP) modes supported by the LHM slab to the spontaneous decay are studied at length. We find that the atomic decay near a LHM slab is much different from that near a dielectric slab or metal slab. The first---the dielectric slab with arbitrary thickness---supports at least two guided modes (one for TE polarized and one for TM polarized), but LHM slab may support none of the guided mode for certain thickness. The second---the atom near the LHM slab---may decay through both TE- and TM-polarized SPP, but the atom near the metal slab can decay only through TM-polarized SPP. The third, when the LHM slab supports only TE-polarized SPP modes, the atom near such slab cannot couple to the SPP mode when its dipole moment is perpendicular to the interface. Even if LHM contains weak loss, above analysis is also valid, and the decay rate directly related to material's losses (defined by the decay through dissipation here) can be distinguished from the total decay rate. Most interesting, we find that the decay through SPP will be larger than the decay through dissipation when the atom is placed at an appropriate position. Our results will give constructive reference to the design and fabrication of the quantum device made of LHM.