Artificial Dielectric Superlattices with Broken Inversion Symmetry

Abstract

A variety of three-constituent superlattice patterns were made in atomic layer-by-layer films, with patterns breaking inversion symmetry giving effective permanent bias fields ranging up to about 200 kV/cm. Dielectric constants at room temperature were nearly ${10}^3$, with loss tangents under 0.01. Most of the response came from discrete dipoles comprising multiple unit cells, but without any ferroelectric phase transition.