Combination of informational storage and logical processing based on an all-oxide asymmetric multiferroic tunnel junction

Multiferroic tunnel junctions (MFTJs) have already been proved to be promising candidates for application in spintronics devices. The coupling between tunnel magnetoresistance (TMR) and tunnel electroresistance (TER) in MFTJs can provide four distinct resistive states in a single memory cell. Here we show that in an all-oxide asymmetric MFTJ of La0.7Sr0.3MnO3 /PbZr0.2Ti0.8O3 /La0.7Te0.3MnO3 (LSMO/PZT/LTMO) with p-type and n-type electrodes, the intrinsic rectification is observed and can be modified by the ferroelectric polarization of PZT. Owing to the combined TMR, TER and diode effects, two different groups of four resistive states under opposite reading biases are performed. With two parallel asymmetric junctions and the appropriate series resistance, the coexistence of logic units and quaternary memory cells can be realized in the same array devices. The asymmetric MFTJ structure enables more possibilities for designing next generation of multi-states memory and logical devices with higher storage density, lower energy consumption and significantly increased integration level.