Differential conductance of planar microcontacts formed by a conductive probe

The differential conductance in microcontacts is shown to be a non-monotono us fucntion of bias voltage. It is revealed that the differential conductan ce is unipolar and depends on the sign of the bias voltage, which implies t he geometrical and structural asymmetry of the manufactured structures. Pec uliarities of the differential conductance are observed in a set of nonline ar current-voltage characteristics formed on a single microstructure by pro be anodizing. The values of "jumps" of the differential conductance of quas i-one-dimensional microcontacts do not agree with theoretical values for qu antum wires because of imperfection of those microcontacts.