Graphene Nanoelectronics

Semiconductor technology has taken us a long way by making devices of ever smaller size. But eventually, fundamental physical barriers will pose a huge challenge for further shrinking of present electronic devices, such  as  quantum and coherence effects, high electric fields creating avalanche dielectric breakdowns, heat dissipation problems in closely packed structures, and non-uniformity of dopant atoms and the relevance of single atom defects. The aim of nanoelectronics is to process, transmit and store information by taking advantage of properties of matter that are distinctly different from macroscopic properties. In the context of electrical conduction, the key quantity that characterizes nanoscale systems is the current density (current pre unit area), which is typically orders of magnitude larger than those found in mesoscopic and macroscopic systems.

What will then be the form of future nanoelectronic devices? Can quantum mechanics be used to control device operation? And can they operate at reasonable temperatures? Nanoscale transistors made from graphene may provide ways to address these questions.

Graphene, a one-atom-thick crystal of carbon atoms, is an unusually simple material with startling new properties (for popular introduction see SciAm article by experimental physicists who invented it). Graphite, the common material used in most pencils, is made up of countless layers of graphene. The electrons in graphene behave as (charged) neutrinos of high energy physics,  obeying an equation that resembles the relativistic Dirac equation, moving freely through barriers created by imperfections, and they show quantum effects at room temperature. 

Besides offering a novel playground to test electron transport and interactions in low-dimensional  systems, as well as quantum electrodynamics, the surprising discovery of graphene in 2004 has been accompanied from the outset with numerous efforts to fabricate field-effect transistors (FET). Such carbon nanoelectronic devices utilize   "bulk" graphene  or graphene nanoribbons (rather than usual carbon nanotubes) as a new FET channel while the gate electrodes control the transport between the source and the drain electrodes attached to such channel.

Research Projects:

• first-principles computation of transport properties of graphene nanoelectronic devices composed of thousands of atoms
• noise in graphene devices
• magnetism in  zigzag graphene nanoribbons
• graphene-based spintronic devices.