Debdeep Jena1, Kaustav Banerjee2, Grace Huili Xing1. 1. Department of Electrical Engineering, University of Notre Dame, Indiana 46556, USA, and in the Department of Electrical and Computer Engineering, and Department of Materials Science &Engineering, Cornell University, New York 14853, USA. 2. Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106, USA.