In this paper, inspired by the idea that the hub nodes of a highly
heterogeneous network are not only the bottlenecks, but also effective
controllers in the network synchronizing process, we bring forward an
asymmetrical coupling method where the coupling strength of each node depends
on its neighbors' degrees. Compared with the uniform coupled method and the
recently proposed Motter-Zhou-Kurth method, the synchronizability of scale-free
networks can be remarkably enhanced by using the present coupled method.Comment: 6 pages, 6 figures; to be published in EPJ