Thermoelectricity in Corbino devices in the quantum Hall regime

摘要

We present thermovoltage and conductance measurements in GaAs/AlGaAs samples. We produce thermal gradients by means of a central resistive heater in a Corbino device. In this geometry the themopower measurements are very different from the ones in usual Hall bar configuration. Assuming a linear response we model the transmission function obtaining and predict the transport coefficients. We can infer the difference of temperatures along different pieces of the sample, in good agreement with the measured temperature profile. Finally, we show that the system presents a promising thermoelectric figure of merit reaching, consistent with and efficiency above 0.3 of Carnot.