title: Charge transport through a semiconductor quantum dot-ring nanostructure.
abstract: Transport properties of a gated nanostructure depend crucially on the coupling of its states to the states of electrodes. In the case of a single quantum dot the coupling, for a given quantum state, is constant or can be slightly modified by additional gating. In this paper we consider a concentric dot-ring nanostructure (DRN) and show that its transport properties can be drastically modified due to the unique geometry. We calculate the dc current through a DRN in the Coulomb blockade regime and show that it can efficiently work as a single-electron transistor (SET) or a current rectifier. In both cases the transport characteristics strongly depend on the details of the confinement potential. The calculations are carried out for low and high bias regime, the latter being especially interesting in the context of current rectification due to fast relaxation processes.
authors.affiliation: Department of Theoretical Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Kurpas
authors.forename: Barbara
authors.initials: B
authors.lastname: Kędzierska
authors.forename: Iwona
authors.initials: I
authors.lastname: Janus-Zygmunt
authors.forename: Anna
authors.initials: A
authors.lastname: Gorczyca-Goraj
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Wach
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Zipper
authors.forename: Maciej M
authors.initials: MM
authors.lastname: Maśka