Quantum point contact in a compressible Quantum Hall liquid

We consider electron transport through a quantum point contact between compressible Quantum Hall liquids and derive the contact's impedance function for both diffusive and ballistic regimes of the bulk electron motion. In either regime, the tunneling current deviates from a power-law behavior $I\sim V^{1/\nu}$ expected on the basis of the single-mode chiral Luttinger liquid phenomenology.