Electron-electron scattering in three-dimensional highly degenerate semiconductors

¹ Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, Tianjin University - Tianjin 300072, China
² NCTU - RIKEN Joint Research Laboratory and Institute of Physics, National Chiao Tung University Hsinchu 30010, Taiwan
³ Department of Electrophysics, National Chiao Tung University - Hsinchu 30010, Taiwan

^(a) zhiqingli@tju.edu.cn
^(b) jjlin@mail.nctu.edu.tw

Received: 11 July 2013
Accepted: 12 August 2013

Abstract

We have measured the low-field magnetoresistances of a series of Sn-doped indium oxide thick films in the temperature T range of . The electron dephasing rate as a function of T for each film was extracted by comparing the magnetoresistance data with the three-dimensional weak-localization theoretical predictions. We found that the extracted varies linearly with . Furthermore, at a given T, varies linearly with , where k_F 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 ∼ 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.