Effect of the electromagnetic environment on arrays of small normal metal tunnel junctions: Numerical and experimental investigation

We present results of a set of experiments to investigate the effect of a d issipative external electromagnetic environment on tunneling in linear arra ys of junctions in the weak-tunneling regime. The influence of this resista nce decreases as the number of junctions in the chain increases and ultimat ely becomes negligible. Further, there is a value of external impedance, ty pically similar to 0.5 k Omega at which the half-width of the zero-voltage dip in the conductance curve shows a maximum. Some new analytical formulae, based on the phase-correlation theory, along with numerical results will b e presented.