Electron heating and current scaling in a two-dimensional electron system in close proximity to nanoscale scatterers
Journal
Journal of the Korean Physical Society
Journal Volume
64
Journal Issue
10
Pages
1407-1411
Date Issued
2014
Author(s)
Abstract
We have performed magneto-transport measurements on a two-dimensional electron system (2DES) which is in close proximity to nanoscaled scatterers. Weak localization, as evidenced by negative magnetoresistance, is observed. In this work, we use the extracted phase coherence rate as a thermometer to measure the electron's effective temperature T e in our 2DES when a high driving current I flows through the device. We find that T e ∝ I ~0.52, consistent with 1/τ ep ~ T 2 in two dimensions, where 1/τ ep is the electron-phonon scattering rate. However, the phase coherence rate 1/τ φ ~ T, with a very small offset, is consistent with zero-temperature dephasing. Most importantly, our experimental results are in agreement with the fact that at low temperatures, the dominant phase-breaking mechanism is electron-electron scattering, not electron-phonon scattering. Therefore we are able to investigate both electron-electron scattering and electron-phonon scattering which are, in most cases, difficult to study independently in the linear region. Our data show that the electron heating effect is a very powerful tool for studying semiconductor devices. © 2014 The Korean Physical Society.
SDGs
Type
journal article