1. Department of Physics, University of South Florida, Tampa, Florida 33620, USA
2. Department of Physics, California State University—East Bay, Hayward, California 94542, USA
3. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
4. National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 30201, USA
5. Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA