Saha Suropriya, Golestanian Ramin
Max Planck Institute for Dynamics and Self-Organization (MPIDS), Göttingen, Germany.
Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford, UK.
Nat Commun. 2025 Aug 7;16(1):7310. doi: 10.1038/s41467-025-61728-8.
Non-reciprocal interactions between scalar fields that represent the concentrations of two active species are known to break the parity and time-reversal (PT) symmetries of the equilibrium state, as manifested in the emergence of travelling waves. We explore the notion of nonlinear non-reciprocity and consider a model in which the non-reciprocal interactions can depend on the local values of the scalar fields in such a way that the non-reciprocity can change sign. For generic cases where such couplings exist, we observe the emergence of spatiotemporal chaos in the steady-state. We associate this chaotic behaviour with a local restoration of PT symmetry in fluctuating spatial domains, which leads to the coexistence of oscillating densities and phase-separated droplets that are spontaneously created and annihilated. We uncover that this phenomenon, which we denote as effervescence, can exist as a dynamical steady-state in large parts of the parameter space in two different incarnations, as characterised by the presence or absence of an accompanying travelling wave.
已知代表两种活性物质浓度的标量场之间的非互易相互作用会打破平衡态的宇称和时间反演（PT）对称性，这在行波的出现中得以体现。我们探讨非线性非互易性的概念，并考虑一个模型，其中非互易相互作用可以依赖于标量场的局部值，使得非互易性能够改变符号。对于存在此类耦合的一般情况，我们观察到稳态中出现时空混沌。我们将这种混沌行为与波动空间域中PT对称性的局部恢复相关联，这导致振荡密度和自发产生与湮灭的相分离液滴共存。我们发现，这种我们称为泡腾现象的现象，可以在参数空间的大部分区域以两种不同形式作为动态稳态存在，其特征是伴随行波的有无。
