1. Department of Physics, National Institute of Technology, Kurukshetra-136119, India
2. Department of Physics, J.C. Bose University of Science & Technology, YMCA, Faridabad-121006, India
3. CSIR, National Physical Laboratory, Dr K. S. Krishnan Road, New Delhi-110012, India
4. Gurugram University, Sector-51, Gurugram-122003, Haryana, India