Topological transport control of colloidal particles

• Applicants: Professor Dr. Thomas Martin Fischer; Professor Dr. Daniel de las Heras
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Experimental Condensed Matter Physics ; Theoretical Condensed Matter Physics
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 440764520

In this combined experimental/theoretical project we aim to understand and unravel the role of topology in the transport of magnetic soft matter systems. Topology plays a crucial role in electronic systems protecting the transport of charge and spin against dissipative scattering which in topologically trivial systems usually destroys the transport. In topologically nontrivial electronic systems a whole zoo of new kind of particles originally postulated in high energy physics with unusual transport properties could be found experimentally in medium energy solid state physics. The field is large enough to entertain the solid-state community for more than a decade. In recent work we have shown that similar, albeit not identical, behaviour can be found in soft matter systems, where driven magnetic colloids or self-propelling magnetic bacteria carrying a magnetic moment replace the electrons and periodic magnetic patterns replace the background solid state. Since the transported objects in this case are embedded into a viscous fluid, the transport involves true dissipation which constitutes a major difference to the protection against dissipation in solid state systems. Due to the mesoscopic size of the transported objects the system can be treated by classical instead of quantum physics, which is a second, less relevant, difference to electronic quantum systems. The main purpose of this proposal is to further examine the role topological protection plays in soft matter systems performing both experiments and computer simulations on the transport of driven magnetic colloidal complexes and on self-propelled magnetotactic bacteria. The topological control shall be applied to families of colloidal aggregates, with each family being transported in a different direction at will using polyglot control loops.

• DFG Programme: Research Grants
• International Connection: Poland
• Cooperation Partner: Privatdozent Dr. Maciej Urbaniak