  It is well-known that maximally entangled GHZ states can achieve perfect
teleportation and superdense coding, whereas maximally entangled W states
cannot. However, it has been demonstrated that there exists a special class of
non-maximally entangled W states, called as \textit{W-like} states, which can
overcome this limitation. Therefore, it is of great significance to prepare
such W-like states for efficient quantum communication. Here, we propose two
kinds of novel and efficient fusion schemes for atomic W-like states based on
the large-detuning interactions between several atoms and a single-mode cavity
field, with which large-scale atomic $|\mathcal{W}_{N+M-1}\rangle$ and
$|\mathcal{W}_{N+M+T-2}\rangle$ states can be prepared, respectively, from two
small-scale atomic $|\mathcal{W}_{N}\rangle$ and $|\mathcal{W}_{M}\rangle$
states and three small-scale atomic $|\mathcal{W}_{N}\rangle$,
$|\mathcal{W}_{M}\rangle$ and $|\mathcal{W}_{T}\rangle$ states, by detecting
the states of one or two of the fused atoms. Particularly, although the fusion
process of our scheme involves particle loss, the corresponding success
probability is high and fixed, which may induce high fusion efficiency.
Furthermore, through the investigation of the resource cost and feasibility
analysis, our protocol is simple and feasible under the current experimental
conditions. All these suggest that it provides an alternative strategy for
preparing large-scale atomic W-like states for perfect teleportation and
superdense coding.
