1. Department of Physics, Pachhunga University College, Aizawl 796001, India
2. Condensed Matter Theory Research Group, Department of Physics, Mizoram University, 796004 Aizawl, India
3. Department of Physics, Kurseong College, Darjeeling, 734203 India
4. Centre for Science Education, NEHU, Shillong 793022, India