1. Department of Physics, University of California─Davis, One Shields Avenue, Davis, California 95616, United States
2. Department of Physics, Izmir Institute of Technology, 35430 Izmir, Turkey
3. ICTP-ECAR Eurasian Center for Advanced Research, Izmir Institute of Technology, 35430 Izmir, Turkey
4. Center for Integrated Nanotechnology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States