Programmable nanoscale domain patterns in multilayers

The pattern formation in systems with multiple layers of adsorbate molecules is studied. We consider the presence of two types of molecules in each layer, which are characterized by different dipole moments. The patterns are characterized by the non-uniform distribution of the two molecules. A phase field model is developed to simulate the molecular motion and patterning under the combined actions of dipole moments, intermolecular forces, entropy and external electric field. The study reveals self-alignment, pattern conformation and the possibility to reduce the domain sizes via a layer by layer approach. It is also shown that the pattern in a layer may define the roadway for molecules to travel on top of. This, combined with electrodes embedded in the substrate, gives a great deal of flexibility to guide the molecular motion and patterning.