Establishment of multi-user quantum channel of entangled multi-atom based on cavity QED

We present a scheme for establishing a multi-user quantum channel of multi-atom entangled W states and GHZ states based on cavity QED. Each user has shared EPR pairs with quantum switch during the leisure time of quantum network. An entangled W state is prepared base on two EPR pairs in cavity field by quantum switch at first, and entanglement swapping and direct measurement is operated on the other EPR pairs to establish a quantum channel of W states between three users. In the same way, we can establish a quantum channel of four atoms entangled W state. Three atoms of quantum switch simultaneously interact with cavity field to establish a quantum channel of entangled GHZ states between three users after direct measurement, and we also establish an N users' quantum channel of entangled GHZ states.