▎ 摘　　要

We calculate the density-density response function of biased twisted bilayer graphene (BTBG) and study its plasmon dispersion within the random phase approximation (RPA). At long wavelengths (q -> 0), plasmon dispersion shows local classical behavior omega = omega(0)root q. Unlike the situation in conventional two-dimensional electron gas (2DEG), where the density dependence of the plasmon energy is of the form omega(0) alpha root n (n is the carrier concentration), the plasmon energy omega(0) is independent of the carrier concentration (n) in biased twisted bilayer graphene. Furthermore, the plasmon energy (omega(0)) is also independent of the Fermi energy (mu) which is decided by the carrier concentration (n).