WAVE INTERFERENCE AND ELECTRON-TUNNELING IN ELECTRON WAVE-GUIDE COUPLERS

Two complementary descriptions of the recently proposed electron waveguide couplers, based on wave interference and electron tunneling, are developed through a unified approach. It is shown that there is a threshold transfer length, which is attributed to a necessary threshold energy for the electron to transfer between two waveguides. The relation between the transfer length and tunneling time is rigorously derived. The issue of equivalence between the two pictures is explicitly illustrated, including the case where there is an effective mass difference in the two waveguides. Normalized dimensionless transfer length and energy are introduced to characterize some general features in the electron waveguide couplers. The transfer length and transfer band-width as a function of the electron energy are calculated, and their implications for the device function are discussed. © 1993 Academic Press. All rights reserved.