The embedding method applied to Y-junctions in electron waveguides

The transport properties of a Y-junction have been analysed using a method derived from the embedding method for confined quantum systems. The method is used to calculate the eigenstates and Green function, which are expanded in any convenient basis set and then used to calculate the transmission and reflection coefficients. Results have been obtained for the Y-junction with and without the presence of an external electric field. Current flow studies have been carried out to interpret the transmission results. Vortices appear in the current flow which correspond to nodes in the associated wavefunctions. It has been shown that by carefully selecting the applied electric field and electron energies, the Y-junction can operate as a bistable (flip-flop) device or a simple switch. (C) 1999 Academic Press.