ELECTRON-TRANSPORT PROPERTIES OF A 2-DIMENSIONAL ELECTRON-GAS INTERACTING WITH PHONONS OF A DEFECT-CONTAINING LATTICE - A PARADIGM FOR LAYERED OXIDE SUPERCONDUCTORS

We study the electron-transport properties of a two-dimensional electron gas interacting with phonons of a lattice containing isotope defects. This serves as a heuristic model for the layered oxide superconductors to help understand the anomalous transport properties of these high-T(c) superconductors. Electron-phonon interaction is described by the deformation-potential approximation, and the lattice dynamics is simplified by the continuum approximation. The integral equation describing the vertex corrections to the electron-transport relaxation time is solved numerically. The electrical conductivity and electron thermal conductivity are calculated and examined in search for the Wiedemann-Franz relation. We find that the isotope mass defects only affect the electron-transport properties slightly. Our calculations support the notion that the vertex corrections are important and that they affect the electron-transport properties significantly in these layered oxide superconductors.