Resistive Memristor Coupled with Multilevel Perpendicular Magnetic States

Memristor is an increasingly important research field for in-memory computing (IMC) due to its significant potential in neuromorphic computing. A resistive memristor that can integrate components with nonvolatility and high-density features, such as spintronics, would be a great blessing for the IMC technology. We demonstrate a Pt/Co/NiO device that exhibited multilevel perpendicular exchange bias (EB) with resistive switching (RS) behaviors. It arose from the modulated Co-NiO exchange coupling with the formation/breaking of the conductive filament (CF) within the NiO layer. With atomistic simulation, we show that the multilevel RS stemmed from the modulation of CF size and distribution at the Co-NiO interface, which in turn influenced intermediate levels of EB along the perpendicular direction. It illustrates the possibility of integrating resistive memristors and spintronic devices. Compared with similar studies, our device possesses the advantages of perpendicular magnetic anisotropy and tunable unipolar/bipolar switching.