Researchers from the University of Tokyo, RIKEN and Tokyo Metropolitan University have demonstrated an ultrafast, energy-efficient nonvolatile switching device based on antiferromagnetic Mn₃Sn, achieving reliable operation in the picosecond regime with dramatically reduced power consumption.
The device is built on Mn₃Sn/tantalum heterostructures and utilizes spin–orbit torque (SOT) to switch the magnetic state using electrical pulses as short as 40 picoseconds. This represents a roughly 1,000× speed improvement over conventional nanosecond-scale switching, which has long been a practical limit in current CPU and GPU technologies due to rapidly increasing energy demands at higher speeds.
A key advance in this work is the use of antiferromagnetic Mn₃Sn, which enables highly efficient angular momentum transfer without relying on thermally driven mechanisms. In conventional ferromagnetic systems, pushing switching into the picosecond regime typically results in excessive heating - often reaching several hundred degrees Celsius - leading to poor endurance and limited scalability. In contrast, the Mn₃Sn-based device achieves picosecond switching with significantly reduced heat generation and improved durability.
The reduced power consumption is particularly notable. In the picosecond regime, the device consumes several orders of magnitude less power than comparable ferromagnetic switching systems. This efficiency stems from the intrinsic properties of antiferromagnets, where spin dynamics allow for faster and more direct manipulation of magnetic states via spin–orbit torque.
In addition to electrical switching, the researchers demonstrated that the same device can be driven by optical means. Using a telecommunication-wavelength laser combined with a photoelectric converter, they generated photocurrent pulses of 60 picoseconds that successfully induced switching. This establishes a direct link between optical signals and magnetic memory writing, providing a proof-of-concept for spintronics-based photoelectric conversion.
The combination of ultrafast operation (40 ps electrical switching, 60 ps optical switching), low power consumption, and high endurance positions this approach as a strong candidate for next-generation memory and computing architectures. It also opens a pathway toward integrated optical-to-electrical interfaces for nonvolatile memory, where data carried by light can be directly written into magnetic states without intermediate conversion steps.