From bulk descriptions to emergent interfaces

Controlling interfaces is highly relevant from a technological point of view. In ferroelectric materials, the energetically equivalent states of the polarization likely give rise to the existence of structures at the nanoscale in the form of interfaces (domain walls) which are widely used in sensing, actuation, nonlinear optics and information storage applications. Emergent structural and functional properties of these domain walls are widely studied for their potential integration as active nanoelectronic device components. However, their rich and complex behaviour makes them very difficult to describe theoretically and hence to predict and control. We address this problem by developing Ginzburg-Landau-type models which have the advantage of allowing us to study domain properties in combination with interface characteristics, and that can capture features of realistic realizations of interfaces. I will show how these models can be successfully employed to probe the effects of different experimental protocols over interfaces and domains and to develop new observables to characterize highly irregular interfaces.