NUMERICAL MODELING OF AHARANOV-BHOM SEMICONDUCTOR HETEROSTRUCTURES

THIS DOCUMENT DISCUSSES A PROPOSAL TO PERFORM NUMERICAL SIMULATIONS OF AHARANOV-BOHM (A-B) DEVICES BUILT OF SEMICONDUCTOR HETEROSTRUCTURES. IN THE CALCULATIONS, WE USE THE SCATTERING MATRIX APPROACH TO PROPERLY TREAT THE PROBLEM AT THE JUNCTION BETWEEN THE CONTACTS AND THE TWO CHANNELS OF THE A-B STRUCTURE. THE SCATTERING MATRIX APPROACH ALSO ALLOW TREATMENT OF THE PROBLEM OF IMPURITY SCATTERING INTO BOTH ARMS OF THE DEVICE. THERE ARE SEVERAL ISSUES ADDRESSED IN THIS PROPOSAL. THE FIRST IS AN IMPLEMENTATION OF THE SCTTERING MATRIX APPROACH TO CALCULATE ACCURATELY THE JUNCTION SCATTER WHEN THERE EXISTS A DIFFERENCE OF POTENTIAL BETWEEN BOTH ARMS OF THE AHARANOV-BOHM DEVICE (THE SO-CALLED ELECTROSTATIC A-B EFFECT). THE EFFECT OF MULTIPLE REFLECTIONS AT THE JUNCTIONS CAN THEN READILY BE INCLUDED IN THE CONDUCTANCE MODULATION OF A-B STRUCTURES BY USING THE TECHNIQUE FOR CASCADING SCATTERING MATRICES. SUCH CALCULATIONS WILL BE PERFORMED TO INVESTIGATE THE IMPORTANCE OF MULTIPLE REFLECTIONS ON THE PERFORMANCE OF ELECTROSTATIC A-B SEMICONDUCTOR HETEROSTRUCTURES AND THE INFLUENCE OF IMPURITY SCATTERING ON THE PERFORMANCE OF A-B DEVICES WILL BE INVESTIGATED. ALSO, THE ELECTRON WAVE FUNCTION AS A FUNCTION OF INCIDENT ENERGY WILL BE COMPUTED. THIS LAST STEP IS NEEDED TO CALCULATE THE IMPORTANCE OF SPACE-CHARGE EFFECTS IN A-B DEVICES.