Thermoelectricity without absorbing energy from the heat sources
Journal article, 2016

We analyze the power output of a quantum dot machine coupled to two electronic reservoirs via thermoelectric contacts, and to two thermal reservoirs - one hot and one cold. This machine is a nanoscale analogue of a conventional thermocouple heat-engine, in which the active region being heated is unavoidably also exchanging heat with its cold environment. Heat exchange between the clot and the thermal reservoirs is treated as a capacitive coupling to electronic fluctuations in localized levels, modeled as two additional quantum dots. The resulting multiple-dot setup is described using a master equation approach. We observe an "exotic" power generation, which remains finite even when the heat absorbed from the thermal reservoirs is zero (in other words the heat coming from the hot reservoir all escapes into the cold environment). This effect can be understood in terms of a non local effect in which the heat flow from heat source to the cold environment generates power via a mechanism which we refer to as Coulomb heat drag. It relies on the fact that there is no relaxation in the quantum dot system, so electrons within it have a non thermal energy distribution. More poetically, one can say that we find a spatial separation of the first law of thermodynamics (heat to work conversion) from the second law of thermodynamics (generation of entropy). We present circumstances in which this non thermal system can generate more power than any conventional macroscopic thermocouple (with local thermalizalion), even when the latter works with Gamut efficiency.

Quantum transport

Thermocouples

Energy harvesting

Coulomb drag

Quantum thermodynamics

Thermoelectricity

Author

R. S. Whitney

Grenoble Alpes University

R. Sanchez

Spanish National Research Council (CSIC)

F. Haupt

RWTH Aachen University

Janine Splettstoesser

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Physica E: Low-Dimensional Systems and Nanostructures

1386-9477 (ISSN)

Vol. 75 257-265

Areas of Advance

Nanoscience and Nanotechnology

Subject Categories

Condensed Matter Physics

DOI

10.1016/j.physe.2015.09.025

More information

Latest update

3/10/2022