TUNNELING INTO THE EDGE OF A COMPRESSIBLE QUANTUM HALL STATE

We present a composite-fermion theory of tunneling into the edge of a compressible quantum Hall system. The tunneling conductance is non-Ohm ic, due to slow relaxation of electromagnetic and Chern-Simons field d isturbances caused by the tunneling electron. Universal results are ob tained in the limit of a large number of channels involved in the rela xation. The tunneling exponent is found to be a continuous function of the Hall resistivity p(xy), with a slope that is discontinuous at fil ling factor nu = 1/2, in the limit of vanishing bulk resistivity p(xx) . When nu corresponds to a principal fractional quantized Hall state, our results agree with the chiral Luttinger liquid theories of Wen and Kane, Fisher, and Polchinski.