Electron-electron scattering in three-dimensional highly degenerate semiconductors

Abstract

We have measured the low-field magnetoresistances of a series of Sn-doped indium oxide thick films in the temperature T range of 4-35 K. The electron dephasing rate 1/t. as a function of T for each film was extracted by comparing the magnetoresistance data with the threedimensional weak-localization theoretical predictions. We found that the extracted 1/t. varies linearly with T-3/2. Furthermore, at a given T, 1/t. varies linearly with k(F)(-5/2) F l(-3/2), where kF is the Fermi wave number, and l is the electron elastic mean free path. These features are well explained in terms of the small-energy-transfer electron-electron scattering time in three-dimensional disordered conductors. This electron dephasing mechanism dominates over the electron-phonon scattering process because the carrier concentrations in our films are similar to 3 orders of magnitude lower than those in typical metals, which resulted in a greatly suppressed electron-phonon relaxation rate. Our result is the first quantitative demonstration of this unique three-dimensional electron-electron scattering time in experiments. Copyright (C) EPLA, 2013