Science Tokyo Researchers Demonstrate Electric Control of Nanoscale Magnetism

Researchers at Science Tokyo have demonstrated a way to reverse magnetization in nanoscale structures using an electric field instead of an electrical current, a development that could eventually help reduce the energy used by magnetic memory devices.

The team worked with nanodots made from bismuth ferrite with cobalt substitution, a multiferroic material known as BFCO. These materials have coupled electric and magnetic properties, allowing researchers to influence a magnetic state by changing the material's electric polarization. The researchers fabricated BFCO nanodots measuring about 190 nanometres and directly observed how their internal polarization changed when an electric field was applied.

The work addresses a growing challenge in computing. Cloud services, artificial intelligence and data centres are driving demand for increasingly large amounts of data storage and processing, while conventional methods of writing magnetic information can lose energy as heat.

Electric Fields Change the Magnetic State

The researchers found that applying an electric field caused the polarization structure inside the BFCO nanodots to reorganise. An initial polarization arrangement changed into a centre-divergent structure, with polarization vectors pointing outward from a central region.

That change in electric polarization was accompanied by a change in the direction of the magnetic moment. Rather than simply flipping the magnetic state, the magnetic moment rotated within the material's preferred plane, providing a controllable way to alter the magnetic configuration.

The researchers were able to observe this relationship by combining two imaging techniques. Piezoresponse force microscopy was used to map changes in electric polarization, while scanning nitrogen-vacancy centre magnetometry detected the associated magnetic fields. Bringing the two measurements together allowed the team to directly connect the restructuring of electric polarization with the reversal of magnetization.

Why the Nanoscale Matters

The BFCO structures used in the experiment were only about 190 nanometres across. At that scale, controlling electric and magnetic properties with precision becomes particularly important for developing smaller electronic and memory components.

A major advantage of the approach is that it does not require an electrical current to reverse the magnetic state. Conventional current-based magnetic memory technologies can generate Joule heating as current passes through a device, resulting in energy loss. An electric-field-driven mechanism could reduce that loss if it can eventually be translated into practical memory hardware.

The magnetic state is also non-volatile, meaning information stored in the material can remain even after power is removed. That combination—magnetic data retention with electric-field-based writing—is one reason multiferroic materials are being studied for low-power memory applications.

A Possible Route to More Efficient Memory

The researchers' observations also suggest that a single nanoscale structure could support more complex magnetic configurations rather than being limited to a simple binary magnetic switch. Such control could become useful as memory technologies continue to shrink and demand for energy-efficient computing increases.

The findings do not represent a finished memory technology, and significant work would still be needed before BFCO-based devices could be incorporated into commercial hardware. The current result is instead an experimental demonstration that electric polarization can be used to control magnetic information at nanoscale dimensions.

For data centres and AI infrastructure, where the energy cost of storing and moving enormous volumes of information is becoming an increasingly important concern, technologies that can write magnetic information with less energy could eventually have a meaningful role. The Science Tokyo work provides another step toward that goal by showing that electric and magnetic states can be precisely linked inside extremely small structures.