The influence of hydrodynamic interactions on lane formation of oppositely charged driven colloidal suspensions is investigated
using Brownian dynamics computer simulations performed on the Rotne-Prager level of the mobility tensor. Two cases are considered,
namely sedimentation and electrophoresis. In the latter case the Oseen contribution to the mobility tensor is screened due
to the opposite motion of counterions. The simulation results are compared to that resulting from simple Brownian dynamics
where hydrodynamic interactions are neglected. For sedimentation, we find that hydrodynamic interactions strongly disfavor
laning. In the steady state of lanes, a macroscopic phase separation of lanes is observed. This is in marked contrast to the
simple Brownian case where a finite size of lanes was obtained in the steady state. For strong Coulomb interactions between
the colloidal particles a lateral square lattice of oppositely driven lanes is stable similar to the simple Brownian dynamics.
In an electric field, on the other hand, the behavior is found in qualitative and quantitative accordance with the case of
neglected hydrodynamics.
PACS. 82.70.Dd Colloids - 61.20.Ja Computer simulation of liquid structure - 64.70.D- Solid-liquid transitions - 05.70.Ln Nonequilibrium and irreversible thermodynamics