Trapping states of a trapped ion, revisited

Abstract

The vibration of ions in the potential well of an ion trap has served for the first demonstration of laser cooling and is an essential ingredient of concepts for quantum information processing. The ion motion couples to a driven internal ion resonance such that the system obeys a Jaynes-Cummings (J-C) model that predicts coherently generated “trapping states” of the oscillatory excitation known from micro-maser dynamics. In the past, metastable states of the vibrational excitation of an individual trapped Ba ion had been observed. They were tentatively identified with the trapping states of the J-C model. Recently, an extension of this model including the spatial distribution of the light field has been shown to give rise to another type of trapping states that are robust under decoherence. The characteristics of these novel trapping states better represent the previously observed metastable vibronic states.