Effect of screening on slow relaxation of excess conductance in two‐dimensional array of tunnel‐coupled quantum dots

Abstract

The excess conductivity relaxation in two‐dimensional array of tunnel‐coupled Ge/Si quantum dots (QDs) was studied for the samples with Coulomb and screened‐Coulomb interaction in hopping regime. The screening of long‐range electron‐electron (e‐e) interaction in the sample with metal plane, put close to the dot layer, was revealed in the crossover from Efros‐Shklovskii variable‐range hopping to the Mott one. It was shown that the relaxation both in interacting and non‐interacting systems is described by stretched exponential law. Characteristic time for the unscreened sample linearly scales with the exciting field. Screening of the electron‐electron interaction suppresses the dependence of the relaxation behavior on the bias voltage and accelerates the relaxation process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Strong to weak localization transition and two-parameter scaling in a two-dimensional quantum dot array

“…The details of this procedure are described in Ref. 32. The temperature dependencies of the conductance for the samples with and without screening is shown in the Fig.…”