▎ 摘　　要

We develop a theory of plasmon-assisted tunneling in graphene-insulator-graphene heterostructures and reveal the manifestations of such process in current-voltage curves, plasmon emission spectra, and junction electroluminescence. We present a unified framework for evaluation of tunneling due to carrier-carrier Coulomb scattering and due to emission of plasmons; the latter mechanism generally dominates the full inelastic current. Moreover, the plasmon-assisted current and plasmon emission rates possess resonant peaks at voltages providing equal energies, momenta, and group velocities of collective and single-particle interlayer excitations. This resonance is unique to the tunnel-coupled 2d systems of massless electrons and is deeply related to strong interactions between collinear carriers in graphene. The predicted effect can be used for design of efficient nanoscale voltage-tunable sources of photons and surface plasmons.