1. Department of Physics and Technology, University of Bergen,
Allegaten 55, 5007 Bergen, Norway and Research Laboratory of Electronics, Massachusetts Institute of Technology, Massachusetts
02139
2. Department of Physics and Technology, University of Bergen,
Allegaten 55, 5007 Bergen, Norway
3. Institute for Experimental and Applied Physics, University of Kiel, Leibnizstrasse 19, 24098 Kiel, Germany and
Ruprecht Haensel Laboratory, University of Kiel and DESY,
24118 Kiel, Germany
4. Department of Engineering, Institute for Manufacturing, University of Cambridge, Cambridge CB30FS, United Kingdom
5. Research Laboratory of Electronics, Massachusetts Institute of Technology, Massachusetts 02139