Correlated Electronic Phenomena in Ultra-Clean Carbon Nanotubes and Bilayer Graphene Devices

University Of California-Riverside, Riverside CA

Investigators

Abstract

****Technical abstract**** This proposal aims at using low temperature transport measurements to study correlated electron physics in graphene and nanotubes, which have emerged as nearly ideal one- or two-dimensional electron systems. The first program focus is the study of electron liquids and solids, such as Wigner crystal states in nanotubes and bilayer graphene, and fractional quantum Hall states in the latter. The second focus is novel interaction-driven insulating states, such as the Mott insulating state in carbon nanotubes, with neutral low-energy excitations and unconventionally charged excitations, and the rich spectrum of insulating phases predicted for bilayer graphene, which are expected to exhibit magnetic ordering or spontaneous layer polarization. In addition to deeper understanding of correlated phenomena in nanostructures, the broader impact of this project includes graduate students mentoring, integrating undergraduate education with physics research, e.g. by contributing to the "UCR Undergraduate Research Journal", and mentoring students from under-represented groups. Via participation in UCR's Nanotechnology Outreach Program, the yearly "Summer Physics Academy" at UCR for high school teachers, and supervising local high school interns, this program is expected to positively impact the science and engineering education in local communities. ****Non-technical abstract**** Compared to bulk materials, nanostructured materials often exhibit emergent new properties. For instance, electronic interactions are mostly negligible in bulk materials, but often dominate in one- or two-dimensional (1D or 2D) systems, where electrons' movements become correlated, so much so that the electrons themselves can solidify to form a crystal. Understanding these novel phenomena is not only crucial to the continued miniaturization of electronics, but may also enable new functionalities and devices. This project investigates such novel liquid and solid phases of electrons and interaction-driven insulating states in two archetypal nanostructured systems: graphene, which is a one-atom thick 2D layer of carbon, and carbon nanotubes, which are essentially 1D rolled up tubes of graphene. In addition to deeper understanding of electron behavior in nanostructures and the potential for the development of electronics with novel functionalities, this project's broader impact includes graduate student mentoring, integrating undergraduate education and research, and engaging students from under-represented groups. Via participation in UCR's Nanotechnology Outreach Program, the yearly "Summer Physics Academy" for high school teachers, and supervising local high school interns, this program is expected to positively impact the science and engineering education in local communities.