Dr. Angus Gale adjusts a micro-manipulator in a quiet Sydney lab, where a stack of atomically thin layers — no thicker than a few sheets of paper laid edge to edge — could help crack one of quantum computing’s toughest challenges. At the University of Technology Sydney, Gale and his team have discovered that twisting layers of hexagonal boron nitride (hBN) can dramatically shift the color and wavelength of light emitted by quantum emitters, tiny defects that act as single-photon sources. This breakthrough offers a new way to fine-tune the building blocks of future quantum technologies, from unhackable communication networks to ultra-precise medical sensors.
Quantum emitters have long intrigued scientists, but their real-world use has been limited by how difficult they are to control. Most materials like diamond or silicon carbide lock emitters into fixed properties. But hBN is different — it’s layered like slices of cheese, as Dr. Gale puts it, allowing researchers to peel, twist, and reassemble the material with precision. This flexibility gives scientists a rare 'knob' to tune quantum behavior on demand. In their experiments, the team repeatedly lifted, rotated, and restacked hBN layers, achieving a shift in light emission far greater than what’s typically possible in quantum systems.
The magnitude of the shift was striking. While most tuning methods alter emission by a fraction of an electronvolt, the twist in hBN produced a change significantly beyond that, opening new pathways for engineering quantum light. “Rather than trying to make hBN defects behave like a traditional solid-state host, we took advantage of hBN’s own strength: its thin, layered, twistable structure,” said Gale. This approach flips the script — instead of forcing new materials to mimic old ones, the team is harnessing what makes hBN unique.
Supervising researcher Professor Igor Aharonovich sees the discovery as a gateway to new physics. “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 kind of emergent behavior is the hallmark of twistronics, a rapidly growing field where angle-dependent quantum effects lead to unexpected properties. For quantum technologies, this means greater control over photon emission — a critical requirement for quantum computing and secure communications.
The implications stretch from cybersecurity to healthcare, where quantum sensors could detect disease at the molecular level, or improve GPS accuracy to within centimeters. While practical devices are still on the horizon, this work brings them closer. By turning the twist of a nanoscale layer into a powerful tuning tool, the Sydney team isn’t just advancing quantum science — they’re reimagining how we build it.