This project is co-funded by the Electronic and Photonic Materials Program and the Condensed Matter Physics Program.
Non-technical Description: Going beyond classical digital electronics to devices based on quantum switches is a goal of modern materials research. Graphene grown on trenches etched in silicon carbide have recently shown incredible electronic and magnetic properties that potentially offer a new platform for quantum-based electronics. Conductivities 100 times larger than theoretical predicted maximums are now obtainable. However, the physical origin of these amazing properties is not yet clear. This research project aims to understand the detailed structure of sub-50 nanometer graphene ribbons and to develop new ways to reproducibly grow and alter their electronic properties. The societal impact of developing these graphene ribbons for near room-temperature quantum-switching networks would have far reaching impacts. In addition to the influence on technology, the project will train undergraduate students in this new field, as well as educating high-school science teachers so that they may better advise their students on the rewards of scientific and engineering professions.
It has recently been shown that graphene grown on the sidewalls of SiC trenches has exceptional transport properties with mobilities exceeding predicted limits for 2-dimentional graphene by more than two orders of magnitude [Nature 506, 349-354 (2014)]. The high degree of order implied by these exceptional properties offers an opportunity to make significant advances in graphene electronics. However, the physical origin of the novel room-temperature ballistic transport in these ribbons is not understood. This proposal's goal is to correlate the nanostructure of the graphene sidewall ribbons with their measured band structure. The research team intends to uncover the role of strain, substrate bonding, and finite size effects on the electronic properties of these unique ribbons and their spectacular transport. The team uses a broad set of high-resolution surface sensitive probes that allow the research to go beyond transport experiments alone to directly measure their electronic structure. It employs high-resolution angle resolved photoemission to measure their electronic band structure and correlate those results with ribbon structure measured by scanning tunneling microscopy, low energy electron microscopy and transmission electron microscopy.
