1. Department of Physics & Astronomy, University of Waterloo, Waterloo, ON, Canada, N2L 3G1
2. Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada, N2L 3G1
3. Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
4. Center for Quantum Physics, Faculty of Mathematics, Computer Science and Physics, University of Innsbruck, Innsbruck A-6020, Austria
5. NIC, DESY, Platanenallee 6, D-15738 Zeuthen, Germany
6. Perimeter Institute for Theoretical Physics, Waterloo, ON, Canada, N2L 2Y5