Coulomb blockade in a superlattice of normal tunnel junctions

The effects of Coulomb blockade are studied in many normal tunnel junctions connected in series. Such a structure is a natural way for creating the small capacitance necessary for Coulomb blockade. The amplitude of single-electron tunneling oscillations is exponentionally small at high temperature and is proportional to the number of junctions. The resistance of a voltage-biased superlattice at high temperature has an activated temperature dependence. The activation energy goes to zero at some threshold voltage proportional to the number of the junctions. © 1990 The American Physical Society.