When a quantum dot is subjected to a thermal gradient, the temperature of electrons entering the dot can be determined from the dots thermocurrent if the conductance spectrum and background temperature are known. We demonstrate this technique by meas
uring the temperature difference across a 15 nm quantum dot embedded in a nanowire. This technique can be used when the dots energy states are separated by many kT and will enable future quantitative investigations of electron-phonon interaction, nonlinear thermoelectric effects, and the effciency of thermoelectric energy conversion in quantum dots.
