Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Dr Sarah Loos, University of Cambridge
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).