Experiments on the thermoelectric properties of quantum dots

Publication date: Available online 29 August 2016 Source:Comptes Rendus Physique Author(s): Artis Svilans, Martin Leijnse, Heiner Linke Quantum dots (QDs) are good model systems for fundamental studies of mesoscopic transport phenomena using thermoelectric effects because of their small size, electrostatically tunable properties and thermoelectric response characteristics that are very sensitive to small thermal biases. Here we provide a review of experimental studies on thermoelectric properties of single QDs realized in two-dimensional electron gases, single-walled carbon nanotubes and semiconductor nanowires. A key requirement for such experiments is to have some methods for nanoscale thermal biasing at one's disposal. We briefly review the main techniques used in the field, namely, heating of the QD contacts, side heating and top heating, and touch upon their relative advantages. The thermoelectric response of a QD as a function of gate potential has a characteristic oscillatory behavior with the same period as is observed for conductance peaks. Much of the existing literature focuses on the agreement between experiments and theory, particularly for amplitude and line-shape of the thermovoltage V th . A general observation is that the widely used single-electron tunneling approximation for QDs has limited success in reproducing measured V th . Landauer-type calculations are often found to describe measurement results better, despite the large electron–electro...
Source: Comptes Rendus Physique - Category: Physics Source Type: research