1. Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
2. Undergraduate Program, Indian Institute of Science, Bangalore 560012, India
3. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560012, India
4. Theoretical Sciences Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur
P.O., Bangalore 560064, India