▎ 摘　　要

We show strong effects of a weak and smooth (on the magnetic length) superlattice potential on edge magnetoplasmons (EMPs) at the armchair edge, with a smooth steplike electrostatic lateral confining potential of a wide graphene channel in the nu = 2 quantum Hall effect regime. The superlattice potential leads to an essential enlargement of a number of EMPs descending from two fundamental EMPs in the absence of superlattice. For the wave vector k(x) within the first Brillouin zone, the EMPs show as the regions of acoustical or quasiacoustical dispersion, with a finite value of group velocity, so the regions with frequency gaps, where a group velocity is nullified at some k(x). We obtain that for k(x) -> 0 the frequency tends to zero only for two EMPs and for other EMPs it obtains finite values. Strong dependence of dispersion relations of the EMPs from the period of the superlattice a(0) and the distance d from a metallic gate is shown; in particular, for a typical size of a gap, for a characteristic value of the frequency and k(x) at which the group velocity is reduced to zero. At the frequency that corresponds to zero group velocity of pertinent fundamental EMP branch the response of the system should present a strong resonance.