Four-state ferroelectric spin-valve

This work is licensed under a Creative Commons Attribution 4.0 International License.Spin-valves had empowered the giant magnetoresistance (GMR) devices to have memory. The insertion of thin antiferromagnetic (AFM) films allowed two stable magnetic field-induced switchable resistance states persisting in remanence. In this letter, we show that, without the deliberate introduction of such an AFM layer, this functionality is transferred to multiferroic tunnel junctions (MFTJ) allowing us to create a four-state resistive memory device. We observed that the ferroelectric/ferromagnetic interface plays a crucial role in the stabilization of the exchange bias, which ultimately leads to four robust electro tunnel electro resistance (TER) and tunnel magneto resistance (TMR) states in the junction.I.F. acknowledges the Beatriu de Pinós postdoctoral scholarship (2011 BP-A 00220) from the Catalan Agency for Management of University and Research Grants (AGAUR-Generalitat de Catalunya). Work in part supported by the German Research Foundation (DFG) via SFB 762. The Beatriu de Pinós 2011BP-A00220 postdoctoral grant is acknowledged by I.F.Peer Reviewe