1. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
2. Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
3. Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
4. Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA