We measure the temperature of a 2D electron gas in GaAs from the thermopower of a one-dimensional ballistic constriction, using the Mott relation to confirm the calibration from the electrical conductance. Under hot electron conditions, this technique shows that the power loss by the electrons follows a T5 dependence in the Gruneisen-Bloch regime, as predicted for acoustic phonon emission with a screened piezoelectric interaction. An independent measurement using conventional thermometry based on Shubnikov-de Haas oscillations gives a T3 loss rate; we discuss reasons for this discrepancy.
@article{arxiv.cond-mat/9809201,
title = {A Thermometer for the 2D Electron Gas using 1D Thermopower},
author = {N. J. Appleyard and J. T. Nicholls and M. Y. Simmons and W. R. Tribe and M. Pepper},
journal= {arXiv preprint arXiv:cond-mat/9809201},
year = {2009}
}
Comments
4 pages and 5 figures, To appear in Phys. Rev. Lett. Vol. 81 (Oct 12 issue)