2 8 M ar 1 99 7 Tunneling into the edge of a compressible Quantum Hall state

We present a composite fermion theory of tunneling into the edge of a com-pressible quantum Hall system. The tunnel conductance is non-ohmic, due to slow relaxation of electromagnetic and Chern-Simons field disturbances caused by the tunneling electron. Universal results are obtained in the limit of a large number of channels involved in the relaxation. The tunneling exponent is found to be a continuous function of the filling factor ν, with a a slope that is discontinuous at ν = 1/2 in the limit of vanishing bulk resistivity ρ xx. When ν corresponds to a principal fractional quantized Hall state, our results agree with the chiral Luttinger liquid theories of Wen, and Kane, Fisher and Polchinski.