▎ 摘　　要

The propagation loss of surface plasmon polaritons (SPPs) on metal nanowires (NW) has limited their applications in integrated nanophotonic devices. In order to reduce propagation loss, the ohmic loss and leaky radiation when NWs placed on substrates should be restrained. In this work, through integration with graphene, the ohmic loss can be decreased and the leaky radiation of hybridized plasmon modes H-1 and H-2 mode can be prominently suppressed, resulting in the reduced propagation loss. Finite element method (FEM) has been utilized for theoretical calculations, which matches the experimental results well. Our work demonstrates a feasible and effective method to reduce the propagation loss.