Solving defect in quantum material could see spaceships powered by light

25 Feb 2020

Image: © Omar/

Researchers working towards a future of quantum computers and light-powered spaceships have made a major discovery.

Futurists envision a time when quantum technologies, aircraft and spaceships could be fuelled simply by the momentum of light. However, before this can become a reality, researchers need to discover bright, on-demand and predictable sources of light.

To that end, a team of material scientists, physicists and engineers from Stanford University, Harvard and the University of Technology Sydney has looked at one potential source: hexagonal boron nitride.

This material can emit bright light as a single photon at a time at room temperature, making it easier to use compared with alternative quantum sources.

However, hexagonal boron nitride has a major downside in that it emits light in a rainbow of different hues, making it impossible to control. The team’s research – published in Nature Materials and led by researcher Jennifer Dionne – wanted to find the source of this multicolour emission in order to harness it.

On a path to ‘exciting quantum optical tech’

The source was pinpointed to atomic defects in the material, eventually leading to a new theory on how to predict the colour of defects by accounting for how light, electrons and heat interact in the material.

Over the course of hundreds of experiments, the team bombarded the material with electrons and visible light and recorded the pattern of light emission. It also studied how the periodic arrangement of atoms in hexagonal boron nitride influenced the emission colour.

“Materials can be made with near atomic-scale precision, but we still don’t fully understand how different atomic arrangements influence their opto-electronic properties,” Dionne said.

“Our team’s approach reveals light emission at the atomic-scale, en route to a host of exciting quantum optical technologies.”

In order to one day control these defects, the team envisions strategic placements of quantum emitters, as well as being able to turn the emissions on and off for future quantum computers.

Colm Gorey was a senior journalist with Silicon Republic