Abstract

The field of stochastic thermodynamics has greatly advanced our understanding of the fundamental principles that govern living and artificial nonequilibrium systems. A key concept is the stochastic entropy production, which explicitly quantifies the breaking of time-reversal symmetry on the mesoscale. However, so far, little attention has been paid to the thermodynamic implications of non-conservative interactions, such as retarded, i.e., time-delayed and nonreciprocal interactions, which cannot be represented by interaction Hamiltonians, contrasting all interactions traditionally considered in statistical mechanics and thermodynamics. Such interactions indeed emerge commonly in biological, chemical and feedback systems, and are widespread in active matter. In this talk, I will use simple time- and space-continuous Langevin models to discuss technical challenges and unexpected physical phenomena induced by nonreciprocity [1] and time delay [2,3]. For example, when reversed in time, the dependence of a delay process on its past transforms into a dependence on its own future, entailing acausality; which has nontrivial consequences for the thermodynamic arrow of time. The total entropy production is then composed not only of the usual contributions of heat release and Shannon entropy change, but also of an information-theoretic term. Likewise, the entropy balance of a system that is nonreciprocally coupled to another entity contains the information flow, giving rise to a generalised second law [1]. We show that a sufficiently strong information flow can generate a heat current against a temperature gradient.

[1] Loos and Klapp, NJP 22 , 123051 (2020).

[2] Loos and Klapp, Sci. Rep. 9, 2491 (2019).

[3] Loos, Hermann, and Klapp, Entropy 23, 696 (2021).