Coherent Trapping Of A Three-level Atom In Circularly Polarized Light

In this paper, we prove that for a three-level atom in a circularly polarized electromagnetic wave, there is a coherent superposed state of its two states such that when the atom is initially in the state, under the zero-order approximation, the atom is always in the state hereafter, while the occupation probabilities that the atom is in other states are zero; under the first-order approximation, the atom is nearly in the state, while the occupation probabilities that the atom is in other states near zero.