Slanted coupling of one-dimensional arrays of small tunnel junctions

We have studied the electrostatic problem of the slanted coupling of two on e-dimensional (1D) arrays with equal junction capacitances C, equal stray c apacitances C-o, equal coupling capacitances C-c, and with both arrays bias ed. In the weak coupling limit (C-c/C much less than 1), we obtain an analy tic solution for the potential profile and the corresponding Gibbs free ene rgy, and we derive threshold voltages for various charge transport modes. O ur results show that C-0, C-c, and the bias voltage V-1 all play important roles in determining the threshold voltage of the system. In the small stra y capacitance limit (C-0/C much less than 1), the threshold voltage is prop ortional to 1/C, while in the large stray capacitance limit (C-0/C much gre ater than 1), the threshold voltage becomes independent of C. Also, in the small C-c/C limit, single electron tunneling always has a lower threshold v oltage than that of the electron-hole and mixed tunneling. In addition, we find that V-1 has a more dramatic effect on the electron-hole tunneling thr eshold voltage than on that of the single electron tunneling, i.e., at some favored value of C-c/C a small change in V-1 can switch the transport of t he system from single electron to electron-hole transport. (C) 1998 America n Institute of Physics. [S0021-8979(98)02824-2].