A useful imperfection
A tiny flaw can sometimes be useful. Researchers have made a light source inside silicon, a material used in computer chips. It can send out single photons. A photon is one tiny packet of light.
The source uses a defect called a W center. Here, “defect” means a change in the usual arrangement of atoms, the building blocks of matter. A W center contains three extra silicon atoms tucked into that arrangement.
Baptiste Lefaucher, Yoann Baron and their colleagues reported the experiment in Nature Communications on October 28, 2026. It is a laboratory light source, not a finished quantum computer.
Putting the light source in place
The team used a mask that worked like a stencil. Tiny holes let silicon ions—silicon atoms with an electric charge—enter selected spots. Heating the chip then helped form W centers.
Next, the researchers made a small silicon disk with rings around it. This structure is called an optical cavity. It helps the W center send light into a pattern that instruments can collect.
Placement matters because the cavity works best when the W center is near the right spot inside it. The team lined up the cavity with the mask hole. But this did not guarantee one working W center at every site. Only some sites produced usable devices with one W center.
What the tests showed
The researchers tested the chip at 10 kelvin, far below freezing. Its light was near-infrared, which human eyes cannot see.
With a steady laser shining on the source, the instruments detected about 1.29 million photon counts per second at the source’s brightness limit. This was a detected count rate, not a promise to deliver that many useful photons to a circuit.
A separate test used weak laser flashes. The team reported 93% single-photon purity, with an uncertainty of two percentage points. This measure describes how well the light avoids containing extra photons. It does not mean every flash successfully delivers one photon.
Stronger flashes reduced that purity. Energy left after a stronger flash could make the W center send out another photon.
Why it matters—and what is missing
Single photons could carry information through future light-based quantum chips. Making their sources at chosen locations could help connect them to other chip parts.
There is still work to do. The source sometimes stopped emitting briefly. The study also did not demonstrate photons that were alike enough for all the quantum tasks the researchers hope to perform. Building many reliable, connected sources remains a goal.
Read the research
Read the peer-reviewed accepted paper, published October 28, 2026, and its complete accepted text. The earlier author manuscript was revised January 23, 2026.