1. Computational
Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
2. Department
of Mathematics, University of California, Berkeley, California 94720, United States
3. Hefei
National Laboratory for Physical Sciences at Microscale, Department
of Chemical Physics, and Synergetic Innovation Center of Quantum Information
and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China