A stochastic approach to two-level ion dynamics driven by light beams

The probability distribution of a two-level ion confined in a harmonic trap and perturbed by the absorption and emission of photons is calculated. The ion is assumed to be excited by a light beam and relaxes back either by induced emissions or irreversible spontaneous emissions. The photon-ion interaction is modeled as a perturbing noise acting on the ion by modifying its energy and momentum. The current calculations reproduce the quantum results of the laser cooling of ions in static traps in the heavy particle limit. © 1995.