Title: Large polaron evolution in anatase TiO2 due to carrier and temperature dependence of electron-phonon coupling,
Abstract: The electronic and magneto transport properties of reduced anatase TiO2
epitaxial thin films are analyzed considering various polaronic effects.
Unexpectedly, with increasing carrier concentration, the mobility increases,
which rarely happens in common metallic systems. We find that the screening of
the electron-phonon (e-ph) coupling by excess carriers is necessary to explain
this unusual dependence. We also find that the magnetoresistance (MR) could be
decomposed into a linear and a quadratic component, separately characterizing
the transport and trap behavior of carriers as a function of temperature. The
various transport behaviors could be organized into a single phase diagram
which clarifies the nature of large polaron in this material.