Dr. Angus Gale carefully lifts a flake of hexagonal boron nitride—no thicker than a few atoms—twists it slightly, and places it back down, like adjusting a vinyl on a turntable. With that tiny rotation, the quantum light emitted from defects within the material shifts dramatically in color, a phenomenon that could redefine how we build future quantum technologies. In a breakthrough published in Science Advances, researchers from the University of Technology Sydney, the University of Minnesota, and Kyung Hee University have demonstrated a new way to control quantum light sources by simply twisting atomically thin layers of hBN, a material often called 'white graphene.'
Quantum light sources—tiny defects that emit single photons—are essential for quantum computing, ultra-secure communications, and next-generation sensors. But until now, controlling their output has been like tuning a radio with a brick: possible, but extremely limited. Most solid-state systems, like those in diamond or silicon carbide, offer only minimal shifts in emission. The UTS-led team’s approach flips the script by embracing hBN’s layered nature instead of fighting it.
By rotating one layer of hBN relative to another—like twisting two slices of molecular cheese—they achieved emission shifts far larger than previously thought possible. The team didn’t just set a fixed angle and observe; they repeatedly picked up, twisted, and restacked the layers, proving the method is dynamic and reversible. This level of control is unprecedented. “Rather than trying to make hBN defects behave like traditional solid-state hosts, we took advantage of hBN’s own strength: its thin, layered, twistable structure,” said Dr. Gale.
The implications go beyond the lab bench. Professor Igor Aharonovich, who supervised the research, explains that twisting layered materials can unlock entirely new physical behaviors. “You can take two layers that don’t do much on their own, put them together at a specific angle, and suddenly you have a completely different system,” he said. That principle—already famous in 'twistronics' with graphene—now extends to quantum photonics.
This tunability could accelerate the development of quantum networks, where precise photon wavelengths are critical, or ultrasensitive biosensors that detect disease markers at the single-molecule level. Unlike rigid bulk materials, hBN’s flexibility offers a reconfigurable platform, opening doors to on-demand quantum devices.
As quantum technologies inch toward real-world use, this twist-controlled approach offers a rare combination: simplicity, precision, and scalability. The future of quantum light may not come from building bigger machines—but from turning a layer just a few degrees.