**Author details**

Uday Dadwal1 \* and Rajendra Singh<sup>2</sup>

1 Nanoscale Research Facility (NRF), Indian Institute of Technology Delhi, New Delhi, India

2 Department of Physics, Indian Institute of Technology Delhi, New Delhi, India

\*Address all correspondence to: udadwal@gmail.com

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
