Nonvolatile control of switchable anomalous valley Hall effect in GdF2/Sc2CO2 multiferroic heterostructure

In two-dimensional valleytronics, the controllability of anomalous valley Hall effect is the key to its practical application. However, most of the previously proposed control methods are volatile or irreversible. Here, using first principles calculations, we demonstrate that the GdF2/Sc2CO2 multiferroic heterojunction can exhibit nonvolatile switching of its electronic band structures. Interestingly, the polarization switching of the ferroelectric monolayer induces movement in the valley polarization band of GdF2, enabling manipulation of the valley Hall effect. This allows the memory state encoded in the ferroelectric monolayer to be read out via the anomalous valley Hall signal of the heterostructures. The switchable anomalous valley Hall effect can also be achieved by applying biaxial strain in the GdF2/Sc2CO2 multiferroic heterojunction. By harnessing this intriguing anomalous valley Hall effect switching characteristic, we develop a nonvolatile valleytronics memory device. This work provides a way to achieve nonvolatile control in valleytronics and promotes the design of memory devices.