CNR NANO - Istituto Nanoscienze Consiglio Nazionale delle Ricerche

- 16.11.2017 - Nest Seminar Hervé Courtois
Date & Venue:Thursday 16 November 2017 - 15:00
NEST seminar room

Speaker:Hervé Courtois (Institut Néel, CNRS et Université Grenoble Alpes, Grenoble, France)

Title:Thermal Conductance of a Single-Electron Transistor

Abstract: The flow of heat at the microscopic level is a fundamentally important issue, in particular if it can be converted into free energy via thermoelectric effects. The ability of most conductors to sustain heat flow is linked to the electrical conductance via the Wiedemann-Franz law. While the understanding of quantum charge transport in nano-electronic devices has reached a great level of maturity, heat transport experiments are lagging far behind, for two essential reasons: (i) unlike charge, heat is not conserved and (ii) there is no simple thermal equivalent to the ammeter. A metallic island connected to a source and a drain through tunnel junctions exceeding the Klitzing resistance and under the influence of a gate electric field constitutes a Single-Electron Transistor (SET). The Wiedemann-Franz law is expected to hold in an SET only at the charge degeneracy points in the limit of small transparency, where the effective transport channel is free from interactions, and is violated otherwise. I will report on the measurements of both the heat and charge conduction through a metallic SET, with both quantities displaying a marked gate modulation. A strong deviation from the Wiedemann-Franz law is observed when the transport through the SET is driven by the Coulomb blockade, as the electrons flowing through the device are then filtered based on their energy.

For information, please contact:Stefan Heun (9472) - stefan.heun@nano.cnr.it

Info stefan.heun@nano.cnr.it

Link http://neel.cnrs.fr/?lang=fr