Quasiparticle Mass Enhancement And Fermi Surface Shape Modification In Oxide Two-Dimensional Electron Gases

We propose a model that is intended to qualitatively capture the electron-electron interaction physics of two-dimensional electron gases formed near transition-metal oxide heterojunctions containing t(2g) electrons with a density much smaller than one electron per metal atom. Two-dimensional electron systems of this type can be described perturbatively using a GW approximation, which predicts that Coulomb interactions enhance quasiparticle effective masses more strongly than in simple two-dimensional electron gases, and that they reshape the Fermi surface, reducing its anisotropy.