FeRroElectric control of Spin-charge interCOnversion

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Oxide compounds are usually highly ionic, with metal and oxygen ions carrying large positive and negative point charges. When inversion symmetry is broken as in ferroelectrics or at surfaces or interfaces, oxides can thus harbour large electric fields. This unleashes a quantum phenomenon known as the Rashba spin-orbit coupling that allows the generation of spin currents from charge currents and vice versa without ferromagnets, circumventing their drawbacks to perform these tasks. In the FRESCO project, we will combine the advantages of Rashba-driven spin-orbitronics phenomena with the ultralow switching energy of ferroelectrics. Building upon our demonstrations of giant spin-charge conversion at polar oxide interfaces and of non-volatile electoresistance in ferroelectric tunnel junctions, we will aim at a non-volatile electrical control of interconverted spin and charge currents in materials systems combining Rashba spin-orbit coupling with ferroelectricity. Guided by first-principles calculations, we will design and explore several families of atomically engineered polar heterostructures combining oxides and transition metal compounds. We will assess their spin-charge interconversion efficiency, its controllability by electric fields and its connection with the energy dependent spin Berry curvature. We will harness this controllability in spin-based non-volatile logic architectures operating through ferroelectricity-controlled spin-charge conversion. Building upon this, we will propose and explore several classes of devices including light-activated sources of spin currents based on photoferroelectricity, reconfigurable non-volatile logic gates, and tuneable THz sources and modulators. FRESCO will pioneer a new approach to generate spin currents and manipulate the static (or dynamic) magnetic states by electric fields beyond conventional magnetoelectricity, but retaining its advantageous low operating power, with a view towards attojoule electronics.