Entangled state generation via adiabatic passage in two distant cavities

A scheme is proposed for the generation of a two-atom entangled state and an N-atom W state in two distant cavities via adiabatic passage. In the scheme, since only laser fields applied to an atom need be changed, the property can effectively reduce the number of operations for implementing the scheme in experiment. And there are no excited states involved during the operation process, so the atom's spontaneous emission can be omitted approximately. Furthermore, the scheme is robust against the amplitude fluctuations of some experimental parameters.