Environmentally activated tunneling events in a hybrid single-electron box

O-P. Saira, M. Möttönen, V.F. Maisi, J.P. Pekola

Research output: Contribution to journalArticleScientificpeer-review

23 Citations (Scopus)

Abstract

We have measured individual tunneling events and Coulomb step shapes in single-electron boxes with opaque superconductor–normal metal tunnel junctions. We observe anomalous broadening of the Coulomb step with decreasing temperature in a manner that is consistent with activation of first-order tunneling events by an external dissipative electromagnetic environment. We demonstrate that the rates for energetically unfavorable tunneling events saturate to finite values at low temperatures, and that the saturation level can be suppressed by more than an order of magnitude by a capacitive shunt near the device. The findings are important in assessing the performance limits of any single-electronic device. In particular, master-equation-based simulations show that the electromagnetic environment realized in the capacitively shunted devices allows for a metrologically accurate charge pump based on hybrid tunnel junctions.
Original languageEnglish
JournalPhysical Review B: Condensed Matter and Materials Physics
Volume82
Issue number15
DOIs
Publication statusPublished - 2010
MoE publication typeA1 Journal article-refereed

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