Abstract: | We present two physical schemes for concentrating three-atom W state based on the same interaction model which involves two
three-level atoms, a cavity field and a classical field. Both schemes introduce only one auxiliary atom. The first scheme
involves only one measurement. There is one more measurement on the auxiliary atom in the second scheme, but the interaction
time is simple in form and there is no single-qubit operation on the auxiliary atom. Moreover, both schemes are insensitive
to cavity decay and within the current cavity quantum electrodynamics (QED) technique. |