Every electron is like a spinning top: it twirls around its own axis. This rotation is called spin. In conventional electronics, we don't use spin — only charge. But that's a missed opportunity: if we learn to control spin, chips could become faster and more efficient. The problem is that in silicon, the main material of electronics, spin is quickly lost, especially in p-type silicon, where charge is carried by "holes."

Researchers in Japan have found a way to extend spin's lifetime. They took a layer of p-type silicon and placed a magnetic material, Mn2CoAl, on top: it's a so-called spin gapless semimetal. Between them, they inserted a thin film of magnesium oxide, which helps electrons with the right spin hop into the silicon. The result is a pathway where spin can travel without getting lost.

The scientists measured how long the spin persists. At room temperature, it's 0.68 nanoseconds. That's short, but enough to send a signal about a micron. When cooled to 5 K, the spin lasts even longer—4.11 nanoseconds. The temperature dependence is weak, pointing to a specific relaxation mechanism — Bir–Aronov–Pikus. In simple terms, spin is lost due to interaction with "holes," not impurities.

This result matters for the future: if spin can be preserved in silicon at room temperature, we could build spin transistors and memory that consume far less energy. Silicon is already in every fab — no need to invent new materials, just add a magnetic layer.