The primary thrust of our research is to explore how electronic structure changes on small length scales affects the macroscopic properties of materials. In particular: how interfaces affect transport properties (eg. in 5-atom thick gate oxides we have used atomic-scale electron energy loss spectroscopy to place fundamental physical limits on device scaling - Nature paper and and comments); the role of electronic structure in controlling the cohesion of interfaces (Phys. Rev. Lett.); and the first detection and real-space characterization of individual dopant atoms and clusters buried inside crystals (Nature, Nature Materials, comments and Opinion). In many cases, our tool of choice will be an atomic-resolution electron microscope, and we are always looking to develop new methods that advance the technique. Areas of interest: Atomic-scale perovskite heterostructures: atom-by-atom design of materials that do not exist in nature, explored for extreme dielectric and nonlinear properties. Physical limits placed by interfacial electronic structure and atomic-scale chemistry on the scaling of integrated circuits. Development of high-resolution, low-dose methods for electron imaging and tomography of organic and biological nanostructures. Nanoparticle-based waveguide lightsources at telecommunications wavelengths - growth and physical characterization Development of new electron microscopy methods and instrumentation

	Three-dimensional imaging of nanostructures using electron tomography.
	Characterization of Carbon Corrosion-Induced Structural Damage of PEM Fuel Cell Cathode Electrodes Caused by Local Fuel Starvation Work in collaboration with General Motors through the Cornell Fuel Cell Institute.
	"Atomic-Scale Chemical Imaging of Composition and Bonding by Aberration-Corrected Microscopy", D. A. Muller, L. Fitting Kourkoutis, M. Murfitt, J. H. Song, H. Y. Hwang, J. Silcox, N. Dellby, O. L. Krivanek, Science 319, p. 1073 (2008)" Cornell Chronicle: A STEM in Color Science Daily: New Electron Microscope Identifies Individual Color-coded Atoms Analytical Chemistry: Electron microscopy comes into focus
	Searching for "interface phases" - states of matter not present in the bulk materials, but stabilized by the structural and electronic boundary conditions at interfaces "Superconducting Interfaces Between Insulating Oxides", N. Reyren, S. Thiel, A. D. Caviglia, L. Fitting Kourkoutis, G. Hammerl, C. Richter, C. W. Schneider, T. Kopp, A.-S. Ruetschi, D. Jaccard, M. Gabay, D. A. Muller, J.-M. Triscone, J. Mannhart, Science 317, 1196-1199 (2007) Cornell Chronicle: Exotic atomic interfaces