Experimental study of Rabi-type oscillation induced by tunneling modes in effective near-zero-index metamaterials

A special cavity based on effective near-zero-index paired structures containing ɛ-negative and μ-negative materials is realized by using composite right- or left-handed transmission lines. When an artificial magnetic "atom" is put into the cavity, unusual Rabi-type splitting appears because of the strong coupling between the artificial atom and the localized tunneling mode. The direct time domain energy exchanges between the cavity and the "atom" are experimentally observed after excited by a short pulse signal. Within the "atom" field attenuation time, more than one oscillations appear. Rabi-type splitting and the Rabi-type oscillation period are invariant with the scaling changes of the length but vary with the positions where the "atom" is put with different field intensity. Moreover, the decay time of Rabi-type oscillation becomes longer when the tunneling mode possesses smaller linewidth, which is in good agreement with numerical simulations.