Slanted coupling of one-dimensional arrays of small tunnel junctions

We have studied the electrostatic problem of the slanted coupling of two one-dimensional (1D) arrays with equal junction capacitances C, equal stray capacitances C0, equal coupling capacitances Cc, and with both arrays biased. In the weak coupling limit (Cc/C≪1), we obtain an analytic solution for the potential profile and the corresponding Gibbs free energy, and we derive threshold voltages for various charge transport modes. Our results show that C0, Cc, and the bias voltage V1 all play important roles in determining the threshold voltage of the system. In the small stray capacitance limit (C0/C≪1), the threshold voltage is proportional to 1/C, while in the large stray capacitance limit (C0/C≫1), the threshold voltage becomes independent of C. Also, in the small Cc/C limit, single electron tunneling always has a lower threshold voltage than that of the electron-hole and mixed tunneling. In addition, we find that V1 has a more dramatic effect on the electron-hole tunneling threshold voltage than on that of the single electron tunneling, i.e., at some favored value of Cc/C a small change in V1 can switch the transport of the system from single electron to electron-hole transport. © 1998 American Institute of Physics