My group is in the physics department at the University of Arizona. I am also a member of the Chemical Physics program and associate editor of APL Materials. Our research is focused on studying low-dimensional systems using a combination of scanning probe microscopy and electrical transport measurements.  Currently, we are investigating three systems, graphene, carbon nanotubes and semiconductor quantum dots.

Graphene is a unique system because of its two-dimensional structure as well as linear dispersion relation. This dispersion relation causes the electrons to behave as massless particles, Dirac fermions, with an effective speed of light that is about 300 times slower than in light in vacuum. The two-dimensional structure of graphene makes it ideal to study with scanning probe microscopy because all of the atoms lie at the surface. We are investigating ways to probe and control the electronic properties of mono and bilayer graphene using low temperature scanning probe microscopy.
The one-dimensional nature of carbon nanotubes means that interaction effects are very important for their electronic and optical properties.  This leads to phenomena ranging from Luttinger liquid behavior to strong exciton binding.  Scanning tunneling microscopy provides extremely high-resolution information about the local density of states in these materials which will provide insight into these interactions.

We are also developing new scanning probe microscopy techniques to image electron wavefunctions inside quantum dots.  This will allow the study of effects such as coherence, electron-electron interactions and the spatial extent of the Kondo screening cloud.  These types of measurements are impossible to do without the spatial information provided by scanning probe microscopy techniques.

If you are interested in joining the group as a post-doc, Ph.D. student or undergraduate please contact me at leroy at physics.arizona.edu. The group equipment calendar can be found here.