Physics of Ferroelectric Interfaces: An Attempt at Nanoferroelectric Physics

Abstract

Experiments on devices can be regarded as part of basic physics. Here, theoretical analyses of devices using the interface in a ferroelectric junction reveal novel basic properties unknown in conventional experiments. Devices using interfaces in ferroelectric junctions are grouped into two types: (1) the lateral-type, or field-effect, devices that use the transconductance, i.e., the conduction parallel to the interface; and (2) the vertical-type, or diode-like, devices, in which the conduction is perpendicular to the interface and the current flows through the ferroelectric. The discussion below concentrates on the field-effect type (1). On the other hand, the other type of devices  have recently attracted intense interest due to the resistance RAM (R-RAM). Additionally, modulation of the tunneling current and the photovoltaic effect have been demonstrated . Details of these topics will be discussed elsewhere. We start our journey by assuming for the present that the ferroelectric is an ideal insulator.