An analytical study on electronic density of states and conductance of typical nanowires

We study the electrical coherent transport properties of typical molecular nanowires attached to the simple metallic leads. We present a detailed theoretical description of these systems in the framework of Green’s function theory, using the nearest neighbor tight-binding approximation. We also calculate their electronic density of states and transmission coefficient. The results reveal that in the linear structures, increasing number of the branches decreases electron tunneling strength in the gap area. Further, in the cyclic structures there are some antiresonances in the conductance coefficient depending on the geometry of molecules or atomic positions in the unit cell at the center wire.