Institut für Theorie der Kondensierten Materie (TKM)
A non-equilibrium system as a demon

Seminar über Theoretische Festkörperphysik


Janine Splettstoesser


18.05.2020 14:00


This talk will take place as an online event.


Chalmers University of Technology, Göteborg, Sweden


Christian Spanslätt Rugarn


Maxwell demons are creatures that are imagined to be able to reduce the entropy of a system without performing any work on it. Conventionally, such a Maxwell demon's intricate action consists of measuring individual particles and subsequently performing feedback.
In this talk, I will show that already much simpler setups can act as demons: we have recently demonstrated [1] that it is sufficient to exploit a non-equilibrium distribution to seemingly break the second law of thermodynamics. In this case, neither detection nor feedback on single particles needs to be performed. In contrast, we study a steady-state multi-terminal system, in which a terminal with a non-thermal distribution is used for power production or cooling in a working substance. No overall energy- or particle currents need to flow from the resource to the working substance. This effect is on one hand of fundamental interest due to its apparently paradoxical nature, but can also be of interest for applications, in which non-thermal distributions result as “waste” from the operation of a device.
We have proposed both electronic and optical implementations of this phenomenon, realizable with current technology [1,2]. In order to quantify the performance of these devices, we propose an efficiency which compares entropy production in the resource to entropy reduction in the working substance [3].

[1] R. Sánchez, J. Splettstoesser, R. S. Whitney: Nonequilibrium System as a Demon. Phys. Rev. Lett. 123, 216801 (2019)
[2] R. S. Whitney, R. Sánchez, F. Haupt, J. Splettstoesser: Thermoelectricity without absorbing energy from the heat sources. Physica E 75, 257 (2016)
[3] F. Hajiloo, R. Sánchez, J. Splettstoesser, R. S. Whitney: Work production and cooling in a non-equilibrium multi-terminal system. In preparation