Interface effects on the shot noise in normal-metal-d-wave superconductor junctions

The current fluctuation in a normal-metal-d-wave superconductor junction is studied for various orientation of the crystal by taking account of the spatial variation of the pair potentials. The properties of the differential shot noise are largely affected by the presence of the Andreev bound states at the interface. The noise power to current ratio at zero voltage becomes zero under the presence of the zero-energy bound states at the tunneling limit. The ratio becomes 4e when a subdominant s-wave component which breaks time-reversal symmetry is induced near the interface.