Applied Materials Physics, Department of Material Science and Engineering, The Royal Institute of Technology, Brinellvagen 23, Stockholm, 100 44, Sweden
Condensed Matter Theory, Institute of Theoretical Physics, The Royal Institute of Technology, AlbaNova University Center, Stockholm, 106 91, Sweden
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States
Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States
Condensed Matter Theory Group, Department of Physics, Uppsala University, Box 530, Uppsala, 751 21, Sweden ; Applied Materials Physics, Department of Material Science and Engineering, The Royal Institute of Technology, Brinellvagen 23, Stockholm, 100 44, Sweden