Effect of the electromagnetic environment on single charge tunneling

H. Grabert und G.-L. Ingold

in: Computations for the Nano-Scale, hrsg. von P. E. Blöchl, C. Joachim und A. J. Fisher, NATO ASI Series E, Bd. 240, S. 245–256 (Kluwer, 1993)

Coulomb charging effects in ultrasmall tunnel junctions sensitively depend on the electromagnetic environment of the junction. Detailed theoretical predictions on Coulomb blockade phenomena in junctions shunted by arbitrary environmental impedances are now available both for the case of normal tunnel junctions and Josephson junctions. For the standard case of a low impedance environment most of the striking single charge tunneling effects predicted in the past are washed out by zero point fluctuations of the electromagnetic environment, however, interesting signatures of charge quantization are observable in the current-voltage characteristics. The effect of electromagnetic fluctuations is less pronounced for multijunction circuits where distinct Coulomb gap structures occur due to the charge quantization on the metallic islands between the junctions.