Condensate formation in a chiral lattice gas

Abstract

We investigate the formation of condensates in a binary lattice gas in the presence of chiral interactions. These interactions differ between a given microscopic configuration and its mirror image. We consider a two-dimensional lattice gas with nearest-neighbour interactions, to which we add interactions involving favoured local structures (FLSs) that are chiral. We focus on FLSs that have the shape of the letter L and explore condensate formation through simulations and analytical calculations. At low temperature, this model can exhibit four different phases that are characterised by different periodic tiling patterns, depending on the strength of interactions and the chemical potential. When particle numbers are conserved, some of these phases can coexist. We analyse the structure and surface tension of interfaces between coexisting phases and determine the shapes of minimal free energy of crystalline condensates. We show that these shapes can be quadrilaterals or octagons of different orientation and symmetry.

Keywords

• chirality
• lattice gas
• statistical mechanics
• phase transitions
• condensates