It is generally believed that the biggest challenge to continued scaling of semiconductor electronic devices is the extreme energy dissipation associated with binary switching. The emergence of carbon based graphene and molecular electronics offers certain inherent advantages, such as higher mobility and chemical functionality. We will describe how detailed 'first principles' computational models coupled with numerous experiments have provided an enormous amount of understanding on how electrons flow at the nanoscale, through a combination of interference pathways and localized many-body states. We will then use this overall understanding and our atomistic models to show how switches can operate at very low power, using alternate state variables beyond uncorrelated charges. One class of devices is 'correlated switches' - embodied in nano-magnetic and multiferroic logic, where many spins correlate through exchange interactions and cut down the overall energy cost. An alternate class is 'subthermal switches' where each degree of freedom operates near a phase transition point below the classical ‘Boltzmann-Landauer’ limit. Two examples of this include a nano-mechanical relay with a Van der Waals pull-in force, and chiral tunneling across graphene PN junctions that lead to a gate tunable transport gap, with a high mobility as well as high ON-OFF ratio.
Avik Ghosh did his PhD in physics at the Ohio State University and postdoctoral research in Electrical Engineering at Purdue University. He is currently Associate Professor of Electrical and Computer Engineering at the University of Virginia. He has over 80 refereed papers and book chapters published in the areas of computational nano-electronics, and has given over 90 invited lectures worldwide. He is a Fellow of the Institute of Physics (IOP), senior member of the IEEE, and has received the 2011 IBM Faculty Award, the NSF CAREER Award for 2008-2013, the best paper award at the 2006 ISSSR conference organized by the Army Research Office and the all university teaching award in 2013.