SoftBio Theory Seminar: Irreversibility in fluctuating nonreciprocal systems

27 Jan 2025
Seminars and colloquia
Time
-
Venue
Simpkins Lee Seminar Room
Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Speaker(s)

Dr Sarah Loos, University of Cambridge

For more information contact

Abstract

Abstract: While the action-reaction principle dictates all fundamental physical interactions, the dynamics we effectively observe in complex nonequilibrium systems ubiquitously breaks reciprocity on various scales. I will first show that even for a simple system of two nonreciprocally coupled Brownian particles, nonreciprocity can have surprising thermodynamic implications, such as generating heat flows against a temperature gradient [1]. I will then discuss the impact of nonreciprocal interactions in many-body systems, focussing on two example systems. First, we show that nonreciprocal vision-cone interactions implemented in a two-dimensional XY model can lead to long-range order and directional propagation of defects [2]. Then we consider binary fluids where nonreciprocal interactions can induce travelling wave solutions. Using fluctuating field theories, we show for a wide class of models that close to transitions to travelling states, fluctuations not only inflate, as in equilibrium criticality, but also develop an asymptotically increasing time-reversal asymmetry and associated surging entropy production [2]. The formation of dissipative patterns and the emergence of irreversible fluctuations can both be attributed to a mechanism of mode coupling in the vicinity of critical exception points.

[1] Loos and Klapp, NJP 22, 123051 (2020). 
[2] Martynec, Klapp, Loos, PRL 130, 198301 (2023).
[3] Suchanek, Kroy, and Loos, PRL 131, 258302 (2023).