▎ 摘　　要

We theoretically show that it is possible to coherently control the group velocity of graphene quasiparticles based on tunable electric field effects in both single layer and bilayer graphene p-n-p waveguides, whereby graphene-based coherent buffers and memories could be proposed. We also find that the essential mechanism for the coherent buffering and trapping of quasiparticles can be attributed to interband tunneling through p-n interfaces.