1. Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, MS B262, Los Alamos, New Mexico 87545, United States
2. Center for Integrated Nanotechnologies, Los Alamos National Laboratory, MS K771, Los Alamos, New Mexico 87545, United States
3. Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, United States
4. Theoretical Division, Los Alamos National Laboratory, MS B213, Los Alamos, New Mexico 87545, United States