40-picosecond Mn3Sn spintronic device switches 1,000x faster with no extra heat

Processors have always faced a challenge: speed and heat go hand-in-hand. When electrons move faster through a circuit, they create more heat. This is why data centers use a lot of electricity just to cool their equipment. It's also why making silicon chips faster without overheating has been so difficult.

Now, researchers at the University of Tokyo have found a way around this problem. They've created a magnetic switching device that uses an antiferromagnetic compound. This device can flip its binary state in just 40 picoseconds, creating very little waste heat.

This new work is the first real-world example of spintronic devices that could run up to 1,000 times faster than today's AI accelerators. Crucially, they do this without the heat issues that make high-speed silicon so expensive to operate.

A Leap in Speed

A picosecond is an incredibly short amount of time — one trillionth of a second. Current processors, even the fastest AI chips, switch states in nanoseconds. The difference between a nanosecond and a picosecond is like the difference between one second and seventeen minutes. The Tokyo team's discovery is not just a small improvement; it's a completely new level of speed.

The device is made from Mn3Sn, which is a compound of manganese and tin. It has a unique structure called a kagome lattice. Unlike regular semiconductors that use electrical charge to store information, spintronic devices use both electrical charge and the magnetic spin of electrons.

In Mn3Sn, the electron spins are arranged in a special antiferromagnetic pattern. This gives the material unique properties. It can be switched electrically and read electrically. Importantly, it doesn't create stray magnetic fields that could interfere with other parts.

In the team's test, a 40-picosecond electrical pulse changed the device's magnetic state. It used much less energy than current AI accelerators. The heat usually created by fast switching was minimal, unlike some previous picosecond methods that caused temperature rises of several hundred Kelvin.

Why Heat is a Major Hurdle

The link between speed and heat in traditional chips is a fundamental law of physics. Electrons moving through materials create heat as their kinetic energy turns into thermal energy.

The faster a chip switches, the more energy is lost as heat over time. This is why powerful AI training centers need special cooling systems and use as much electricity as small towns.

Spintronic devices use both charge and spin to handle data. The Tokyo team's device showed that a 40-picosecond electrical pulse could flip its magnetic state with very little heat. It also used much less energy than modern AI accelerators.

This has big implications for data centers. Cooling currently makes up about 40% of their total energy use. A switching technology that works at picosecond speeds without creating a lot of heat could cut down on both cooling needs and the energy used for computing.

What Comes Next

The researchers are careful to explain that this speed boost doesn't directly mean overall computer speed will increase by the same amount. A computer is complex, with many hardware and software parts working together. A faster switch alone has its limits.

Also, Mn3Sn is not silicon. It can't be made using current semiconductor manufacturing methods without major changes. The device shown is a proof-of-concept switch, not a full processor.

Turning this working antiferromagnetic device from a lab in Tokyo into a usable computer part that can be integrated with memory and software will take years of engineering. However, the fundamental physics, which was the most important part to prove, has now been confirmed. This is exactly what the next generation of computing hardware needs as silicon technology reaches its physical limits.

This research was first published in the journal Science.