Dynamical theory of topological defects II: universal aspects of defect motion

Journal article

We present a computational study of the pairwise interactions between defects in the recently introduced non-reciprocal Cahn-Hilliard model. The evolution of a defect pair exhibits dependence upon their corresponding topological charges, initial separation, and the non-reciprocity coupling constant $α$. We find that the stability of isolated topologically neutral targets significantly affects the pairwise defect interactions. At large separations, defect interactions are negligible and a defect pair is stable. When positioned in relatively close proximity, a pair of oppositely charged spirals or targets merge to form a single target. At low $α$, like-charged spirals form rotating bound pairs, which are however torn apart by spontaneously formed targets at high $α$. Similar preference for charged or neutral solutions is also seen for a spiral target pair where the spiral dominates at low $α$, but concedes to the target at large $α$. Our work sheds light on the complex phenomenology of non-reciprocal active matter systems when their collective dynamics involves topological defects

Authors: Romano, J; Mahault, B; Golestanian, R

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: IOP Publishing
• Journal: Journal of Statistical Mechanics: Theory and Experiment
• Volume: 2024
• Issue: 3
• Pages: 033208-033208
• Publication date: 2024-03-27
• DOI: 10.1088/1742-5468/ad2ddb
• EISSN: 1742-5468
• ISSN: 1742-5468
• Language: English
• Keywords: Topology (electrical circuits); Combinatorics; Classical mechanics; Topological defect; Mathematics; Motion (physics); Quantum mechanics; Physics; Theoretical physics