Researchers from the University of Maryland, King Abdullah University of Science and Technology (KAUST), Nankai University, Cornell University, University of Wisconsin–Madison, Oak Ridge National Laboratory, University of California, University of Tennessee, Air Force Research Laboratory and Rice University recently reported the first experimental realization of non-volatile, electrical control of magnetism in a two-dimensional (2D) material system. The collaborative work demonstrates a robust interferroic magnetoelectric coupling in a van der Waals heterostructure made of atomic layers of ferroelectric CuCrP₂S₆ and ferromagnetic Fe₃GeTe₂ - marking a milestone for 2D multiferroic research and energy-efficient spintronic applications.
At the heart of this work lies the long-standing challenge of stabilizing ferroic order in truly two-dimensional materials. While ferroelectric and ferromagnetic phenomena are both well-established in bulk materials, their coexistence in 2D is difficult to maintain due to depolarization fields and thermal fluctuations that destabilize long-range order. The team overcame these limitations by stacking exfoliated layers of the ferroelectric CuCrP₂S₆ and ferromagnetic Fe₃GeTe₂ with atomically clean interfaces, enabling short-range, interfacial coupling between their ferroic orders.
Using precise magneto-optical Kerr and magnetic circular dichroism measurements at 153 K, the researchers demonstrated that switching the polarization state of the CuCrP₂S₆ layer reversibly modified the magnetic coercivity of a 3.8 nm-thick Fe₃GeTe₂ layer by about 14 mT. The coupling exhibited a magnetoelectric control efficiency of around 65%, which is remarkably high for a 2D system. Notably, thicker Fe₃GeTe₂ layers (> 8 nm) showed reduced coupling strength, confirming that the magnetoelectric interaction acts over only a short interfacial range.
Unlike previously reported volatile electric-field effects - often arising from electrostatic doping or piezoelectric strain - this system exhibited a strictly non-volatile response. Once the ferroelectric polarization was switched, the associated change in magnetic anisotropy persisted even after removing the external voltage. This persistence provides unambiguous evidence of genuine ferroelectric–ferromagnetic coupling in a van der Waals heterostructure.
The results suggest that 2D multiferroic heterostructures could play a key role in advancing spintronics beyond charge-based electronics. Non-volatile and reversible electric control of magnetism promises low-power memory elements, spin-based logic, and neuromorphic circuits that rely on electric rather than current-induced control. While the current demonstration operates at cryogenic temperature, the team aims to extend the approach to room-temperature operation and scalable fabrication platforms.
This work represents a step toward integrating atomically thin multiferroics into next-generation, energy-efficient nanoscale devices.