E. Granato et Jm. Kosterlitz, CHARGE GLASS IN 2-DIMENSIONAL ARRAYS OF CAPACITIVELY COUPLED GRAINS WITH RANDOM OFFSET CHARGES, Physical review letters, 81(18), 1998, pp. 3888-3891
We study the effect of random offset charges in the insulator to condu
ctor transition in systems of capacitively coupled grains, as realized
in two-dimensional arrays of ultrasmall Josephson junctions. In the p
resence to disorder, the conductive transition and charge ordering at
nonzero gate voltages are both destroyed for any degree of disorder at
finite temperatures in the thermodynamic limit, but crossover effects
will dominate at finite length scales. The conductance is linear and
thermally activated but nonlinear behavior sets in at a crossover volt
age which decreases as temperature decreases. For large disorder, the
results are supported by Monte Carlo dynamics simulations of a Coulomb
gas with offset charges and are consistent with the thermally activat
ed behavior found in recent experiments. [S0031-9007(98)07499-7].