Measuring Temperature Gradients over Nanometer Length Scales

TL;DR

This paper introduces a method to measure temperature gradients at nanometer scales using quantum dots, enabling detailed studies of thermoelectric effects and electron-phonon interactions in nanoscale systems.

Contribution

The authors demonstrate a novel technique to determine electron temperatures across a quantum dot using thermocurrent measurements, applicable at nanometer length scales.

Findings

Successful measurement of temperature difference across a 15 nm quantum dot

Technique applicable when energy states are separated by many kT

Potential for studying thermoelectric effects at the nanoscale

Abstract

When a quantum dot is subjected to a thermal gradient, the temperature of electrons entering the dot can be determined from the dot's thermocurrent if the conductance spectrum and background temperature are known. We demonstrate this technique by measuring the temperature difference across a 15 nm quantum dot embedded in a nanowire. This technique can be used when the dot's 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.