1. Department of Physics and Astronomy and Advanced Materials Institute; Western Kentucky University; Bowling Green KY USA
2. Department of Physics and Astronomy and The Gatton Academy of Mathematics and Science; 1906 College Heights Blvd Bowling Green KY USA
3. The Gatton Academy of Mathematics and Science; 1906 College Heights Blvd Bowling Green 42101 KY USA
4. Department of Physics; University of Texas Rio Grande Valley; Edinburg TX USA