Schools of skyrmions with electrically tunable elastic interactions

TL;DR

This paper demonstrates that electrically tunable elastic interactions in skyrmions lead to collective behaviors such as schooling, clustering, and cohesion, resembling biological systems and enabling potential applications in dynamic electro-optic materials.

Contribution

It introduces a new class of skyrmion systems with electrically controllable elastic interactions that produce emergent collective behaviors.

Findings

Skyrmions exhibit collective schooling behavior independent of electric field direction.

Reconfigurable multi-skyrmion clustering and large-scale cohesion are observed.

Behavior occurs under conditions similar to liquid crystal displays, enabling potential applications.

Abstract

Coexistence of order and fluidity in soft matter often mimics that in biology, allowing for complex dynamics and applications like displays. In active soft matter, emergent order can arise because of such dynamics. Powered by local energy conversion, this behavior resembles motions in living systems, like schooling of fish. Similar dynamics at cellular levels drive biological processes and generate macroscopic work. Inanimate particles capable of such emergent behavior could power nanomachines, but most active systems have biological origins. Here we show that thousands-to-millions of topological solitons, dubbed "skyrmions", while each converting macroscopically-supplied electric energy, exhibit collective motions along spontaneously-chosen directions uncorrelated with the direction of electric field. Within these "schools" of skyrmions, we uncover polar ordering, reconfigurable multi-skyrmion clustering and large-scale cohesion mediated by out-of-equilibrium elastic interactions. Remarkably, this behavior arises under conditions similar to those in liquid crystal displays and may enable dynamic materials with strong emergent electro-optic responses.