عنوان مقاله [English]
In this paper, we study the electronic conductance of a simple chain -as well as a polyacetylene oligomer- which is connected to three one-dimensional metallic leads. The calculations are based on Green’s function technique within the nearest neighbor tight-binding approach. Two types of conductances, one which is measured between left and right leads and another which is measured between left and top leads, are calculated as functions of energy; and their behaviors are investigated with respect to the position of the top lead connection in the center wire. The results show that the existence and the position of third lead in the center wire strongly effects on the values and behaviors of the mentioned electronic conductances. For polyacetylene case, the value of each conductance at zero energy can be tuned by variation of third lead position.