1. Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, United States
2. Quantum
Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37381, United States
3. Research Center for Solid State Physics
and Materials, School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009, China
4. Department of Physics, University of Ioannina, Ioannina 45110, Greece
5. Department of Physics, Duquesne University, Pittsburgh, Pennsylvania 15282, United States