Regensburg 1998 – scientific programme
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TT: Tiefe Temperaturen
TT 1: Ladungseffekte in Einzelelektronensystemen
TT 1.4: Talk
Monday, March 23, 1998, 10:45–11:00, H 19
Cotunneling in double-island structures — •Teemu Pohjola1,2, Jürgen König2, Herbert Schoeller2, and Gerd Schön2 — 1Materials Physics Laboratory, Helsinki University of Technology, Finland — 2Institut für Theoretische Festkörperphysik, Universität Karlsruhe, 76128 Karlsruhe
We study electron transport through a system consisting of two small metal islands connected in series between two electrodes. We concentrate in the perturbative regime and use the real-time diagrammatic technique to calculate the average charge on the islands and the linear and non-linear conductance of the system. We perform an exact expansion of the diagrams up to O(α2) in the spirit of the recently re-formulated cotunneling theory of [1]. In so doing we find that no cutoff procedure is needed for the physical quantities of interest. As results we find an enhanced renormalization of the conductance peaks and an increasing peak conductance for a decreasing temperature. We also find asymmetric renormalization and broadening of the differential conductance curve for finite voltages. We suggest these effects to be experimentally observable.
[1] J. König, H. Schoeller, and Gerd Schön, Phys. Rev. Lett. 78, 4482 (1997)