1. School of Physics ARC Centre for Quantum Computation and Communication Technology University of Melbourne Parkville VIC 3010 Australia
2. School of Electrical Engineering and Telecommunications ARC Centre for Quantum Computation and Communication Technology UNSW Sydney Sydney NSW 2052 Australia
3. Helmholtz‐Zentrum Dresden‐Rossendorf (HZDR) Dresden 01328 Saxony Germany
4. Leibniz Institute of Surface Engineering (IOM) Leipzig 04318 Saxony Germany
5. RMIT Microscopy and Microanalysis Facility RMIT University Melbourne VIC 3001 Australia