Effect of DC electric field on longitudinal resistance of two dimensional electrons in a magnetic field

TL;DR

This study investigates how a DC electric field influences the longitudinal resistance of two-dimensional electrons in GaAs quantum wells under magnetic fields, revealing resistance suppression linked to electron distribution changes and providing new scattering time measurements.

Contribution

It demonstrates the electric field's suppression of resistance in Landau-quantized 2D electrons and extracts scattering times at high temperatures, extending understanding beyond previous methods.

Findings

Resistance is strongly suppressed at Landau quantization fields.

The electric field scale is proportional to temperature at low T.

Inelastic and quantum scattering times are measured at high temperatures.

Abstract

The effect of a DC electric field on the longitudinal resistance of highly mobile two dimensional electrons in heavily doped GaAs quantum wells is studied at different magnetic fields and temperatures. Strong suppression of the resistance by the electric field is observed in magnetic fields at which the Landau quantization of electron motion occurs. The phenomenon survives at high temperature where Shubnikov de Haas oscillations are absent. The scale of the electric fields essential for the effect is found to be proportional to temperature in the low temperature limit. We suggest that the strong reduction of the longitudinal resistance is the result of a nontrivial change in the distribution function of 2D electrons induced by the DC electric field. Comparison of the data with recent theory yields the inelastic electron-electon scattering time $\tau_{in}$ and the quantum scattering time $\tau_q$ of 2D electrons at high temperatures, a regime where previous methods were not successful.