Plateau behavior in the chiral Luttinger liquid exponent

The current-voltage power law exponent, alpha, for electron tunneling into chiral Luttinger liquids at the fractional quantum Hall edge is found to ex hibit a plateaulike structure at alpha close to 3 as the filling factor, nu , is varied. The presence of a plateau near alpha = 3 strongly suggests a f undamental connection between alpha and the structure of the underlying qua ntum ground states associated with the robust incompressible nu = 1/3 Hall fluid. However, the position in the inverse filling factor where the platea u occurs con vary between samples and appears shifted to values higher than expected from theory.