1. Low Temperature Laboratory, Department of Applied Physics, Aalto University School of Science 1 , P.O. Box 15100, 00076 Aalto, Finland
2. QTF Centre of Excellence, Department of Applied Physics, Aalto University School of Science 2 , P.O. Box 15100, 00076 Aalto, Finland
3. Microelectronics and Quantum Technology, VTT Technical Research Centre of Finland Ltd 3 ., P.O. Box 1000, 02044 VTT, Finland
4. Microelectronics and Quantum Technology, VTT Technical Research Centre of Finland Ltd., QTF Centre of Excellence 4 , P.O. Box 1000, 02044 VTT, Finland