COULOMB DRAG OF EDGE EXCITATIONS IN THE CHERN-SIMONS THEORY OF THE FRACTIONAL QUANTUM HALL-EFFECT

Long-range Coulomb interaction between the edges of a Hall bar changes the nature of the gapless edge excitations. Instead of independent mo des propagating in opposite directions on each edge as expected for a shea-range interaction one finds elementary excitations living simulta neously on both edges, i.e., composed of correlated density waves prop agating in the same direction on opposite edges. We discuss the micros copic features of this Coulomb drag of excitations in the fractional q uantum Hall regime within the framework of the bosonic Chern-Simons La ndau-Ginzburg theory. The dispersion law of these excitations is nonli near and depends on the distance between the edges as well as on the c urrent that flows through the sample. The latter dependence indicates a possibility of parametric excitation of these modes. The bulk distri butions of the density and currents of the edge excitations differ sig nificantly for short- and long-range interactions.