▎ 摘　　要

Terahertz plasma wave (plasmon) localization and velocity control in tapered heterostructure (taper) with double-layer graphene were numerically studied. We employ a simple rigorous theoretical model to find out the plasmon localization length and energy velocity values along the tapered structure. It is shown that the plasmon decelerates while moving from the taper apex and the deceleration process is accompanied with increase of the plasmon wave localization. While moving along the structure from the taper apex, the plasmon energy velocity as well as the plasmon localization length can become nearly an order of magnitude smaller as compared to the values near the taper apex.