1. a National High Magnetic Field Laboratory, Los Alamos National Laboratory , Mail Stop E536, Los Alamos , New Mexico , 87545 , USA
2. d Department of Physics , University of California , Riverside , CA , 92521 , USA
3. b Department of Physics , University of California , Riverside , California , 92521 , USA
4. e Department of Physics , Occidental College , Los Angeles , CA , 90041 , USA
5. c Ames Laboratory and Iowa State University , Ames , Iowa , 50011 , USA