Quantum interference in a stub-constriction structure containing an infinite strength potential barrier

Abstract

We present a theoretical study of electron conductance in a quantum structure containing an infinite strength rectangular potential barrier. The structure we study consists of a quantum wire connected to a stub and a constriction. Conductance results are obtained with and without the scatterer in the channel. Multiple reflections of the electron waves from the stub and the scatterer produce resonance and antiresonance peaks on conductance plateaus. The modulation in conductance is found to be reduced in the presence of the constriction in the structure. Electron conductance through the stub-constriction structure has also been investigated by scanning the potential barrier across the width of the stub, and it has been found that the conductance is heavily modulated. We describe the resonance and antiresonance oscillatory structures in the conductance as due to quantum interference between the incident wave and the electron waves scattered by the boundaries and a potential scatterer.