Finding Topological Charges in Confined Ellipses

The structure of a two-dimensional fluid confined in a circular cavity bounded by a hard wall is investigated using Monte Carlo simulation in NVT ensemble. The fluid consists of hard ellipses with two different aspect ratios. Average density and order parameter are calculated locally to show if any topological charge is formed. The magnitude, location, number of these topological charges, and also their dependence on the radius of the circular cavity are studied here. Different phases are formed by increasing packing fraction of the fluid and it has claimed that the existence and the kind of topological charges both depend on the ellipse’s interaction with the wall (planar or homeotropic), the radius of the circular cavity, and the elongation of particles.