The characteristics of the magnetoconductance of a nonuniform electron waveguide containing various shaped obstacles are investigated by using a model of twohyphen;coupled tighthyphen;binding chains and the transferhyphen;matrix approach. The variation of the magnetoconductance as a function of total magnetic flux Fgr; threading the obstacle region is presented. The effect of the interchain tunneling modulation on the magnetoconductance for doublehyphen;mode and singlehyphen;mode transport processes is different. When the energy of the incident electrons is just above the threshold energy for the opening of the second propagating mode at zero magnetic field, at some magnetic flux, the conductance abruptly decreases owing to the presence of mode quenching. The magnetoconductance for various multiply connected structures and onehyphen;dimensional superlattice (1DSL) type tunneling modulation structures is also evaluated. Owing to the presence of the miniband gaps to be formed by 1DSL structures, different patterns in the magnetoconductance are found.
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