1. Department of Electrical Engineering, Columbia University, 500 W. 120th St., Mudd 1310, New York, New York 10027, United States
2. School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
3. Department of Physics, Belda College, Belda, West Bengal 721424, India
4. Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
5. Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India