Affiliation: | 1. Department of Physics, College of Engineering and Technology, SRM Institute of Science and Technology, Vadapalani Campus, No.1, Jawaharlal Nehru Road, Vadapalani, TN, India;2. School of Physics, Madurai Kamaraj University, Madurai 625 021, India;1. Korea Advanced Institute of Science and Technology, Daejeon, South Korea;2. Virginia Polytechnic Institute and State University, Blacksburg, USA |