Quantum interference effects on the electron conduction through negative-potential regions

Abstract

The quantum interference effects on transport properties of quantum wires including some large obstacles with a negative potential are studied in the presence of a magnetic field. It is found that the magnetoconductance has a quasiperiodic dip structure in the high magnetic field regime. We show that the dips are attributed to an Aharonov-Bohm-type effect and that the period reflects the ring area lying between the inner and outer orbits for the negative-potential region. The effects of the potential edge structure on the conductance are also discussed. The current density around the obstacles and the magnetic field dependence of energy levels are calculated to investigate whole features of the conductance.