Possibility of 2D electron gas on free ferroelectric surface and its effect on domain and size limit

The inclusion of the finite band gap effect changes drastically conventional understanding of the finite size effect and suggests a possible electron generation at the ferroelectric surface contacting with the vacuum and the insulator that can be regarded as a new class of 2-dimensional electron system. The theory uses the macroscopic thermodynamic theory incorporating a quantum confinement effect. The theory predict that the domain configuration in even nm scale platelet has a wide freedom and the size limit is very small which encourages the future of nm scale ferroelectrics. This paper serves as an introduction to this theory.