Quantum Interference on Graphs Controlled by an External Electric Field.

摘要

The authors consider motion of a charged quantum particle on a loop with two external leads which is placed into an electrostatic field. The loop Hamiltonian is chosen in the simplest possible way; in order to join it to the free Hamiltonians describing the leads, we employ a method based on self-adjoint extensions. Under a symmetry requirement, the resulting full Hamiltonian contains four free parameters; each junction is characterized by a pair of them. The system under consideration represents a model of metallic or semiconductor structures that can be fabricated by presently available technologies. Assuming the ballistic regime for electrons in such a structure. The authors calculate the resistance dependence on intensity of the external field. The results suggest the possibility of constructing quantum interference transistors whose size and switching voltage would be much smaller than in the presently used microchips. 41 refs.; 4 figs. (Atomindex citation 19:069530)