3.11 Thermal transport properties

This chapter talks about thermal transport properties of quantized transport. The oscillations in thermopower have been indirectly observed via the measurement of a transverse voltage between two asymmetrically tuned QPCs connected to the same 2D reservoir. The observed oscillations of the transverse voltage are clearly correlated with the steps between quantized plateaux. The current-voltage characteristics of a quantum waveguide geometry with length 0.1 μm are plotted for gate-voltage increments. The experimental setup is shown where the transverse voltage (i.e. V₁ - V₂) is plotted as a function of the gate bias applied to one QPC electrode pair. The comparison with theory was derived under the assumption that there is no net current between 2DEG and the QPC reservoirs. This zero transmission condition allows the chemical potential difference to be directly related to the temperature difference and hence the transverse voltage to be determined.