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A Thermometer for the 2D Electron Gas using 1D Thermopower

N. J. Appleyard·J. T. Nicholls·M. Y. Simmons·W. R. Tribe·M. Pepper
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Abstract

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 $T^5$ 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 $T^3$ loss rate; we discuss reasons for this discrepancy.

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N. J. Appleyard, J. T. Nicholls, M. Y. Simmons, W. R. Tribe, M. Pepper. 1998-09-14. A Thermometer for the 2D Electron Gas using 1D Thermopower. https://doi.org/10.1103/physrevlett.81.3491

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