FEMMES · FerroElectric Multifunctional tunnel junctions for MEmristors and Spintronics

The aim of the project FEMMES is to study the interplay between charge/spin tunneling and ferroelectricity in Ferroelectric Tunnel Junctions (FTJs) composed of two electrodes separated by a ferroelectric tunnel barrier. It will address fundamental issues such as the influence of interfaces and small thicknesses on the ferroelectricity, the dependence of the charge and spin tunneling on the ferroelectric orientation (electroresistance), the impact of the ferroelectricity of the barrier on the magnetism and spin polarisation of the electrodes.I propose to exploit FTJs and the intrinsic low-power of “ferroelectric writing”, to obtain:1) a low-power electrical control of spin polarized electron sources for spintronics in FTJs with magnetic electrodes.2) memristive FTJs mimicking the plasticity of synapses for an exploitation in neuromorphic analog circuits.This will be achieved by a synergetic approach combining:- ab initio calculations to determine the most appropriate combination of ferroelectric materials and electrodes and to obtain a complete description of the impact of the ferroelectric character on the transport properties.- the growth of selected heterostructures and extensive characterization of their structural, ferroelectric and magnetic properties.- the patterning of junctions (at the µm and nm scale) and the investigation of their transport and magnetotransport properties.- the evaluation and optimization of the potential of FTJs as electrically tunable spin sources for spintronics and memristors for neuromorphic circuits.