1. Center for Computing Research, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
2. Département de physique, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
3. Institut quantique, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
4. Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
5. Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney 2052, Australia
6. Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom