Dresden 2017 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 75: Poster Session: Transport 1

TT 75.9: Poster

Thursday, March 23, 2017, 15:00–19:00, P2-EG

Utilizing SETs in single electron counting experiments — •David Reifert, Niels Ubbelohde, Ralf Dolata, Thomas Weimann, and Alexander Zorin — Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig. Germany

We fabricate dynamic quantum dots through a shallow etch process of a GaAs/AlGaAs heterostructure. These quantum dots can be operated as single electron source by periodically modulating one of the barriers of the dot. The resulting current I=e f depends only on the pumping frequency f and the electronic charge e, which enables us to use these pumps as a new quantum current standard. We utilize superconducting aluminum single electron transistors (SETs) as ultra sensitive charge detectors to characterize the performance of such electron pumps. To increase the measurement bandwidth of our detectors we use the RF-SET technology, where we put the SET in a resonant tank circuit and measure the reflectance of this resonator. Besides increasing the bandwidth this technique enables us to multiplex several detectors. We will show the fabrication and operation of our hybrid devices consisting of semiconductor electron pumps and metallic SET detectors. Furthermore, we investigate the performance of semiconductor based SETs as charge detectors and compare them with the superconducting metallic SETs. We then utilize these devices to perform single electron counting measurement, where the electron pump act as an electron source and the SETs detects these electrons, which then will enables us to validate the precision of the pump.