Speaker
Description
Nanoscale devices have access not only to heat, like usual heat engines, but also to other resources, such as information, like in Maxwell demon-based engines, or nonthermal distributions. Furthermore, since fluctuations can be sizeable at the nanoscale, precision, namely how much the noise of the output power is suppressed, is a key performance quantifier for such devices. In this talk, I will present a refrigerator-type device exploiting the thermoelectric effect but fed by a nonthermal resource. The device generates a heat flow from cold to hot in the working substance in the absence of any average particle or energy flow from the resource region,
thereby acting as a “demon”.
Specifically, the device consists of three capacitively coupled quantum dots, one of which is tunnel-coupled to two electronic reservoirs at different temperatures (the working substance) while the other two dots are respectively in contact with a hot and a cold reservoir (the demonic resource).
In such a setup, a finite cooling power can be obtained in the working substance, while the energy exchange with the resource region exactly cancels out on average. At the same time, information is always exchanged, even on average, due to the capacitive coupling between the working substance and the resource region. The proposed system therefore, implements an autonomous demon with fully vanishing heat extraction from the resource.
I will give a comprehensive description of the thermodynamic performance of the proposed autonomous demon by using two complementary approaches: stochastic trajectories and full counting statistics. I will first show that the precision of the cooling power strongly depends on the operation principle of the device. More precisely, the interplay of information flow and counter-balancing heat flows at the trajectory level dramatically impacts the trade-off between cooling power, efficiency, and precision [1]. I will then provide further insights on the operation of the device by analyzing the noise in the input heat flow and cross-correlations between heat currents, evidencing in particular that the output noise – namely cooling power fluctuations – can be made much smaller than the input noise [2].
These results are of relevance for guiding the design of energy-conversion processes exploiting nonthermal resources.
[1] J. Monsel, M. Acciai, R. Sánchez, and J. Splettstoesser, Autonomous
demon exploiting heat and information at the trajectory level,
Phys. Rev. B 111, 045419 (2025).
[2] J. Monsel, M. Acciai, N. Chiabrando, R. Sánchez, and J. Splettstoesser,
Precision of an autonomous demon exploiting heat and information,
arXiv:2510.14578.