Charge Order and Non-Coulombic Short-Range Potentials in the Two-dimensional Electron Gas

Professor Gabor Csathy, Department of Physics and Astronomy, Purdue University

Because of its flat energy bands, the two-dimensional electron gas exhibits a rich set of ground states. These ground states include spontaneously forming stripe and bubble phases. It is believed that such patterns are stabilized when competing long-range and short-range interactions banish uniformity. For these patterns to form, it is therefore critical to have a short-range potential that is non-Coulombic in nature.

In this talk, we will discuss the origin of these non-Coulombic short-range potentials and their manifestation in the proliferation of the electronic bubble phases and in a direct phase transition from the electronic stripe phase to the n=5/2 non-Abelian fractional state. While there are different ways to generate and tune the non-Coulombic short-range potential causing these phenomena, we believe that the primary mechanism for generating the potential arises from the overlap of single-electron wavefunctions with a complex nodal structure.