Collective directional locking of colloidal monolayers on a periodic substrate

We investigate the directional locking effects that arise when a monolayer of paramagnetic colloidal particles is driven across a triangular lattice of magnetic bubbles. We use an external rotating magnetic field to generate a two-dimensional traveling wave ratchet forcing the transport of particles...

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Detalhes bibliográficos
Autores: Stoop, Ralph L.; Straube, Arthur V.; Johansen, Tom H.; Tierno, Pietro
Tipo de documento: Artigo
Estado:Published version
Data de publicação:2020
País:España
Recursos:Universidad de Barcelona
Repositório:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/158946
Acesso em linha:https://hdl.handle.net/2445/158946
Nível de acesso:Acesso aberto
Palavra-chave:Col·loides
Matèria condensada tova
Colloids
Soft condensed matter
Descrição
Resumo:We investigate the directional locking effects that arise when a monolayer of paramagnetic colloidal particles is driven across a triangular lattice of magnetic bubbles. We use an external rotating magnetic field to generate a two-dimensional traveling wave ratchet forcing the transport of particles along a direction that intersects two crystallographic axes of the lattice. We find that, while single particles show no preferred direction, collective effects induce transversal current and directional locking at high density via a spontaneous symmetry breaking. The colloidal current may be polarized via an additional bias field that makes one transport direction energetically preferred.