Double barrier resonant propagation filter

A resonant propagation filter for applications in quantum wire waveguide comprising:

• first and second regions of a first semiconductor material having a first conduction band edge energy;
• and
• a third region of a second semiconductor material with a second conduction band edge energy which is lower than that of said first and second regions, the third region being disposed between said first and second regions;
• a first quantum wire waveguide having a conduction band edge energy similar to the third region;
• wherein the first, second and third regions form a resonant tunneling structure and wherein said resonant tunneling structure is disposed within said electron waveguide such that the lateral dimensions of the resonant tunneling structure are constrained thereby permitting only a predetermined range of electron momenta in a direction of electron propagation and only discrete values of momentum in the lateral directions;
• said filter permitting predetermined propagating modes to pass through said waveguide.