Andreev tunneling in charge pumping with SINIS turnstiles
Low Temperature Laboratory, Aalto University - P.O. Box 13500, 00076 Aalto, Finland, EU
2 Centre for Metrology and Accreditation (MIKES) - P.O. Box 9, 02151 Espoo, Finland, EU
3 Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology SE-412 96 Göteborg, Sweden, EU
Accepted: 9 September 2011
We present measurements on hybrid single-electron turnstiles with superconducting leads contacting a normal island (SINIS). We observe Andreev tunneling of electrons influencing the current plateau characteristics of the turnstiles under radio-frequency pumping. The data is well accounted for by numerical simulations. We verify the dependence of the Andreev tunneling rate on the turnstile's charging energy. Increasing the charging energy effectively suppresses the Andreev current.
PACS: 74.45.+c – Proximity effects; Andreev reflection; SN and SNS junctions / 85.35.Gv – Single electron devices / 06.20.F- – Units and standards
© EPLA, 2011