Recent efforts by two national labs to build a new quantum network to boost U.S. capabilities in unhackable communication technologies just got a key technology to further those aims.

Researchers at Stevens Institute of Technology have developed an on-chip quantum emitter capable of emitting one photon of light at a time with a previously unattainable spatial resolution and efficiency. This advance could prove key to the development of unbreakable cryptography and quantum computers.

For the past decade, quantum dots have been the de facto approach for creating on-chip quantum emitters. In these quantum emitters, one photon is emitted at a time, as opposed to classical light, where trillions of photons are scattered everywhere.

However, one of the scientists behind that research from over a decade ago was never quite satisfied with how you couldn’t control where the quantum dots would emit their one photon of light. Stefan Strauf, a professor at Stevens and coauthor of this most recent research, described in Nature Nanotechnology, was looking for something other than quantum dots to serve as a material for an on-chip quantum emitter.

“The spatial control is not there for quantum dots because they grow at random locations,” said Strauf. “It is just like throwing molecules from a solution on a wafer and letting them dry out. The quantum dots are not very different than that.”