Zero-bias anomaly in asymmetric contacts

Abstract

The Coulomb electron-electron interaction effect on the tunneling conductance of an asymmetric contact consisting of two nonequivalent two-dimensional electron systems, one clean and the other disordered, is considered. It is shown that the zero-bias anomalies typical for symmetric disordered and clean contacts are strongly modified in the asymmetric clean-disordered contact due to more complicated screening effects and appearance of a new collective mode.