Condensed Matter Theory

Research group

Research theme

Sub department

About

Related research groups

Flow states and transitions of an active nematic in a three dimensional channel

(2020)

Authors:

Santhan Chandragiri, Amin Doostmohammadi, Julia M Yeomans, Sumesh P Thampi

Cell lineage-dependent chiral actomyosin flows drive cellular rearrangements in early C. elegans development

eLife eLife 9 (2020) e54930

Authors:

Lokesh G Pimpale, Teije C Middelkoop, Alexander Mietke, Stephan W Grill

Asymptotically exact theory for nonlinear spectroscopy of random quantum magnets

(2020)

Authors:

SA Parameswaran, Sarang Gopalakrishnan

Designing metachronal waves of cilia

(2020)

Authors:

Fanlong Meng, Rachel R Bennett, Nariya Uchida, Ramin Golestanian

Degenerate states, emergent dynamics and fluid mixing by magnetic rotors.

Soft matter 16:28 (2020) 6484-6492

Authors:

Takuma Kawai, Daiki Matsunaga, Fanlong Meng, Julia M Yeomans, Ramin Golestanian

Abstract:

We investigate the collective motion of magnetic rotors suspended in a viscous fluid under a uniform rotating magnetic field. The rotors are positioned on a square lattice, and low Reynolds hydrodynamics is assumed. For a 3 × 3 array of magnets, we observe three characteristic dynamical patterns as the external field strength is varied: a synchronized pattern, an oscillating pattern, and a chessboard pattern. The relative stability of these depends on the competition between the energy due to the external magnetic field and the energy of the magnetic dipole-dipole interactions among the rotors. We argue that the chessboard pattern can be understood as an alternation in the stability of two degenerate states, characterized by striped and spin-ice configurations, as the applied magnetic field rotates. For larger arrays, we observe propagation of slip waves that are similar to metachronal waves. The rotor arrays have potential as microfluidic devices that can mix fluids and create vortices of different sizes.