Hydrodynamics of active defects

Add to your list(s) Download to your calendar using vCal

• Cristina Marchetti, UCSB
• Tuesday 07 May 2019, 13:00-14:00
• MR11, CMS.

If you have a question about this talk, please contact Professor Mike Cates.

Topological defects play a prominent role in the physics of two-dimensional materials. When driven out of equilibrium in active nematics, disclinations can acquire spontaneous self-propulsion and proliferate to drive self-sustained flows. In this talk I will describe the derivation of an interacting particle description of defects that includes active torques and show that activity drives a non-equilibrium variant of the Berezinskii Kosterlitz-Thouless defect-unbinding transition. On scales larger than the defect separation, the dynamics of the gas of unbound defects can be described by hydrodynamic equations derived by coarse-graining the defects microdynamics. At high activity, nonequilibrium torques combined with many-body screening cause the active disclinations to spontaneously break rotational symmetry, forming a collectively moving defect ordered polar liquid. Finally, I will show that the hydrodynamic theory provides an excellent framework for treating inhomogeneous activity that can be used to pattern and control the dynamics of defects in active fluids.

This talk is part of the DAMTP Statistical Physics and Soft Matter Seminar series.

This talk is included in these lists:

• All CMS events
• DAMTP Statistical Physics and Soft Matter Seminar
• MR11, CMS
• Soft Matter
• bld31

Note that ex-directory lists are not shown.