Approximate calculation of the density of electronic off-resonant states in nanoconstrictions with weak atom-lead coupling

We determine theoretically the density of electron off-resonant states in a one-atom constriction with weak coupling between the atom at the nanoconstriction (nanowire) and the corresponding leads by considering the conductance (which is found to be low) through the wire whose insulating behavior is pointed out. From the expression for conductance, the characteristic electrochemical potential versus current is calculated.