Dumbbell dimer dynamics in three-dimensional chiral fluids

We study the emergent orientational dynamics of a dumbbell dimer—two asymmetric monomers connected by a linking spring—in a three-dimensional chiral environment with odd viscosity. In classical systems with conserved parity symmetry, reciprocal oscillations of a dimer do not lead to rotational motion. Here, through an analytical calculation, we find that the presence of chirality in the system induces rotational dynamics as a function of the expansion/contraction of the dimer. By incorporating thermal fluctuations, we further find that the rotational diffusivity is affected by the coupling between conformational fluctuations and rotational motion. Our results provide insights into problems where the parity symmetry is broken and can be used as a building block to study similar models at the collective level. These problems include multicomponent molecular machines in odd-viscous fluids and systems with charged polymers where oddity is present through external magnetic fields.