1. International Center for Nanodevices, INCeNSE-TBI, Indian Institute of Science Campus, Bangalore 560 012, Karnataka, India
2. Open Academic Research Council, Hooghly 712 235, West Bengal, India
3. Open Academic Research UK CIC, Cambridge CB3 1AT, U.K.
4. International Center for Nanodevices, High Tech Campus Eindhoven, Eindhoven 5656 AE, The Netherlands
5. Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, U.K.