Energy loss rate in silicon inversion layers

The authors report the results of measurements on the rate of heat loss from hot electrons in silicon inversion layers at low temperatures. The results are interpreted in terms of the generation of acoustic phonons and it is found that disorder has a significant effect on this mechanism. In the low-disorder, high-temperature limit the energy relaxation time tau epsilon varies with electron temperature T e as T e -4 . In the high-disorder, low-temperature limit tau epsilon varies as T e -2 . The electron temperature is measured by the effect on the weak two-dimensional localisation which allows the experiment to be performed at low temperatures.