Nonvolatile interfacial magnetoelectric coupling via CISS effect from chiral nanoclusters

The chirality-induced spin selectivity (CISS) effect offers a promising strategy for generating spin-polarized currents, thereby opening new avenues for the development of nonvolatile spintronic devices. Here, we design a heterostructure device composed of a pair of enantiomeric chiral metal nanoclusters, R/S-Ag38 ([(VO4)(V2O7)@Ag38(R/S-BNP)6(p-tBuPhC≡C)24(DMF)6](CF3SO3), R/S-BNP = R/S-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate and p-tBuPhC≡C=4-tert-butylphenylacetylene), and the ferroelectric polymer P(VDF-TrFE). X-ray diffraction analysis reveals that R/S-Ag38 possesses a dumbbell-shaped Ag38 kernel supported by VO43− and V2O74− anions and exteriorly protected by R/S-BNP and p-tBuPhC≡C− ligands. Leveraging the CISS effect of chiral R/S-Ag38, the system enables cooperative coupling between spin and dipolar polarization at the interface. The remanent polarization state of P(VDF-TrFE) enables nonvolatile control of interfacial spin polarization, giving rise to magnetoelectric behavior. Moreover, pulsed voltage response further confirms that ferroelectric polarization modulates spin states within the R/S-Ag38 at the heterostructure. Moreover, circularly polarized light excitation on the heterostructure provides a very critical technical means, enabling circular-polarized photons to regulate both the magnetoelectric coupling strength and the electric dipole strength.