Single and double paramagnetic colloidal particles are placed above a magnetic square pattern and are driven with an external magnetic field precessing around a high symmetry direction of the pattern. The external magnetic field and that of the pattern confine the colloids into lanes parallel to a lattice vector of the pattern. The precession of the external field causes traveling minima of the magnetic potential along the direction of the lanes. At sufficiently high frequencies of modulation only the doublets respond to the external field and move in direction of the traveling minima along the lanes, while the single colloids cannot follow and remain static. We show how the doublets can induce a coordinated motion of the single colloids building colloidal trains made of a chain of several single colloids transported by doublets.
Cite
@article{arxiv.1911.06566,
title = {Colloidal trains},
author = {Mahla Mirzaee-Kakhki and Adrian Ernst and Daniel de las Heras and Maciej Urbaniak and Feliks Stobiecki and Andreea Tomita and Rico Huhnstock and Iris Koch and Jendrik Gördes and Arno Ehresmann and Dennis Holzinger and Meike Reginka and Thomas M. Fischer},
journal= {arXiv preprint arXiv:1911.06566},
year = {2019}
}