1. University of Colorado Boulder, Department of Applied Mathematics, Boulder, CO 80309, USA
2. National Institute of Standards and Technology, Information Technology Laboratory, Boulder, CO 80305, USA
3. University of Colorado Boulder, Center for Theory of Quantum Matter, Boulder, CO 80309, USA
4. University of Waterloo, Institute for Quantum Computing and Department of Physics and Astronomy, Waterloo, Ontario N2L 3G1, Canada
5. NTT Corporation, NTT Basic Research Laboratories, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan