Autonomous quantum absorption refrigerators

We propose a new design for a quantum absorption refrigerator using resonant-tunneling quantum dots. A hot and cold fermionic leads are connected to a very hot central cavity via quantum dots and we analyze situations where the heat from the cavity is absorbed to power a heat current from the cold lead to the hot one. We infer the conditions under which the device operates as refrigerator and identify two distinct regimes where cooling is possible depending on the positions of dot energies (above or below the Fermi energy) which we link to either electron or hole transport. We further study the coefficient of performance and cooling power of the refrigerator which we optimize fine-tuning the energies and level widths of the dots. We identify the thermodynamically reversible energy configurations where the device is Carnot efficient while its cooling power vanishes, and we show that refrigeration is only possible for small values of the level width. Finally, we propose associating an arbitrary number of such refrigerators in series so as to extract heat from various reservoirs at once. We demonstrate how to use this setup for thermal control, that is, how to choose dot energies so that heat currents across the chain match a preassigned spatial distribution.

Ref: arXiv:2010.06024