Transport of electron-hole pairs in arrays of small tunnel junctions

We investigate charge transport in two capacitively coupled 1D arrays of small tunnel junctions, attached to two different circuits. The electron and hole placed in adjacent electrodes of different arrays form a sort of ‘‘exciton’’ that moves as a whole. It was shown that under certain conditions only these excitons contribute to the charge transport along the junction arrays, so that the currents in the circuits are exactly equal in magnitude and opposite in direction. The existence of these excitons provides an interesting possibility to simulate some features of microscopic excitons in a mesoscopic system.