Electronic Properties of Two Dimensional Electron Systems: Exploring the Role of Dimensionality Boundaries and Interfaces.

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****TECHNICAL ABSTRACT****Two dimensional electron systems, by virtue of their reduced spatial dimension and incomplete screening, present exotic electronic properties and novel correlated phases which are unavailable in three dimensional counterparts. To date, in spite of important advances and discoveries made by studying the conventional two dimensional electron systems trapped at semiconductor interfaces, many questions remain open. The work proposed here will employ graphene, one of the latest additions to the family of two dimensional electron systems, to address questions regarding novel electronic properties and correlated electron phases that arise due to the reduced dimensionality, screening, boundaries and chiral nature of the charge carriers at low temperatures and in high magnetic fields. Answering these questions may hold the key to novel application including ultra-fast electronics and building blocks for quantum computers. The experimental probes will include low temperature high-magnetic field scanning tunneling microscopy, scanning tunneling spectroscopy, Landau level spectroscopy and magneto-transport. The proposed research will provide an excellent training ground for young researchers in state of the art nano-fabrication and spectroscopy techniques. In addition, the direct and visually oriented nature of the information from this research project will make it easy to communicate the excitement of physics and nano-science to students and to the general public. ****NON-TECHNICAL ABSTRACT****Everything around us, from the smallest creature to the largest object is three dimensional. Our views and understanding of the world as well as the laws of physics governing it are grounded in this trio of spatial dimensions: length, width and height. What would happen if one of these dimensions were taken away leaving us in a proverbial "flatland". It turns out that strange and counterintuitive phenomena can occur because in such a two-dimensional world quantum mechanics, the theory which describes the behavior of the microscopic world of atoms and electrons, becomes manifest at macroscopic length scales. This project will pursue experiments to probe these new types of quantum phenomena in a recently discovered two-dimensional system, graphene. Graphene a membrane made of crystalline Carbon which is only one atom thick is the closest realization of a truly two dimensional system known to date. The project will employ the most advanced tools of experimental science: nanofabrication, low temperatures, high magnetic fields, atomic resolution scanning tunneling microscopy and spectroscopy, to probe and manipulate the properties of graphene. Possible outcomes include the creation of novel electronic phases with properties that can be tuned by applying a magnetic field or a gate voltage, and devices that could one day serve as building blocks for quantum computers. This project will support the education of young researchers in state of the art science and technological applications providing an excellent training ground for a broad spectrum of scientific careers ranging from academia to the most advanced technology industries.