Imagine you’re at a cricket match between the Chennai Super Kings and Mumbai Indians at the Wankhede Stadium. The crowd is huge, and the energy is thrilling. Suddenly, a group of fans starts a Mexican wave. Soon, hundreds of people stand up and sit down in perfect rhythm, making the wave ripple across the stadium.

This is similar to how a "spin current" works.

• What is a spin current?

Just like the Mexican wave travels through people standing up and sitting down, a spin current moves through a material. Instead of people, it involves tiny particles called electrons, which have a special property called "spin." Spin is like a little arrow inside an electron, pointing either up or down.

In a spin current, electrons quickly pass their spin from one to another—just like the wave moving across the crowd—but the electrons themselves don’t move. The wave in spin currents is all about the transfer of spin states, not the movement of the electrons themselves.

• Why do scientists care?

Spin currents are important because they can help us store more information in computers and make data processing faster. Right now, computers use magnetic hard drives to store data, using the up or down spin states of electrons to represent the 0s and 1s in binary code. Spin currents could make this process faster and more efficient.

Scientists are trying to figure out how to create spin currents that start and stop super quickly. The faster they can make this happen, the better our technology can become.

• What’s the latest discovery?

Recently, scientists made a big breakthrough. They created a spin current in just 2 femtoseconds. (A femtosecond is one quadrillionth of a second—it’s incredibly fast!) This was done using special materials and lasers. The scientists stacked layers of cobalt and platinum, then fired two quick laser pulses at them. The first laser pulse caused the electrons’ spins to go wild, and the second pulse measured how much the spins had changed.

The results showed that a tiny spin current moved between the cobalt and platinum layers in just 2 femtoseconds, setting a new speed record for generating spin currents. This discovery could help build even faster, more powerful computers in the future.

• What’s next?

Now, scientists are trying to figure out if they can use these super-fast spin currents in real devices and maybe even create them in attoseconds, which are even faster than femtoseconds! If they succeed, the future of computers could look very different, with data processing happening at lightning speed.