1. National High Magnetic Field Lab, Florida State University, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
2. Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
3. Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
4. Department
of Mechanical Engineering and Materials Science, Rice University, Houston, Texas 77005-1892, United States
5. Departamento de Física Teórica
de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain