QUANTUM INTERFERENCE IN A STUB-CONSTRICTION STRUCTURE CONTAINING AN INFINITE STRENGTH POTENTIAL BARRIER

We present a theoretical study of electron conductance in a quantum st ructure 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 wa ves from the stub and the scatterer produce resonance and antiresonanc e peaks on conductance plateaus. The modulation in conductance is foun d 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 o f the stub, and it has been found that the conductance is heavily modu lated. We describe the resonance and antiresonance oscillatory structu res in the conductance as due to quantum interference between the inci dent wave and the electron waves scattered by the boundaries and a pot ential scatterer. (C) 1998 American Institute of Physics.