Probing the local temperature of a 2DEG microdomain with a quantum dot: measurement of electron-phonon interaction

Simone Gasparinetti, Fabio Deon, Giorgio Biasiol, Lucia Sorba, Fabio Beltram, Francesco Giazotto

Published 2010-07-01, updated 2012-06-01Version 2

We demonstrate local detection of the electron temperature in a two-dimensionalmicrodomain using a quantum dot. Our method relies on the observation that a temperature bias across the dot changes the functional form of Coulomb-blockade peaks. We apply our results to the investigation of electron-energy relaxation at subkelvin temperatures, find that the energy flux from electrons into phonons is proportional to the fifth power of temperature, and give a measurement of the coupling constant.