DFT investigation of heterostructures with ferroelectric overlayer: 2DEG, Rushba effect, ME coupling

The presence of ferroelectric as a component of heterostructure gives us new outstanding functionality which can be used in possible electronic devises based on it. Due to the presence of spontaneous polarization in the ferroelectric thin film, the two-dimensional gas (2DEG) can occur at the interface. The electronic properties of arising state can be tuned by an external field through the ferroelectric dipoles’ direction change. Besides, the presence of electrostatic field along the ferroelectric field is favorable in the possible structures with spin-orbit (SO) splitting. The control of SO splitting by ferroelectric polarization is a desirable property for spintronic applications. Natural materials demonstrating both gigantic and ideal states of Rashba are extremely rare, so computer simulations could help in this problem. Another property which can be useful for electronic application is magnetoelectric coupling. This property is associated with possibility of controlling the ferromagnetic ordering at the interface due to interactions of spins through conduction electrons and with arising of multiferroic properties of all heterostructure. Multiferroic materials are compounds where at least two order parameters coexist in the same phase. One very important but rather rare group is ferroelectric ferromagnets, which have recently stimulated an increasing number of research activities for their scientific uniqueness and application in the novel multifunctional devices. Magnetoelectric materials are interesting due to the possibility to control magnetic properties by an external electric field. Due to the extraordinary challenge of creating multiferroic compounds, it was essential to create superlattice multicomponent materials as more efficient. So, the present research dedicated to the ab initio study of heterostructures having a ferroelectric as one of the components. The aim is to investigate the possibilities of controlling the interfacial properties (2DEG, Rushba effect, ME coupling) via ferroelectric polarization. The reported study was funded by Russian Scientific Foundation, research project No. 21-12-00179.