A faster and cheaper way to produce quantum nanodiamonds holds promise for medicine and industry

An international team of scientists from three continents led by Dr. Peter Siegler from IOCB Prague has developed a method to create light-emitting quantum centers in nanodiamonds in just minutes. In just one week, this process can produce as much material as conventional methods produce in more than forty years.

Furthermore, the resulting nanodiamonds showed improved optical and quantum properties. This breakthrough brings us one step closer to the industrial production of high-quality, affordable quantum nanodiamonds, which have broad applications in research and technology. The article is published in Advanced functional materials.

The research team has introduced a new procedure called pressure-temperature quantum qubits (PTQ), which takes just four minutes. The diamond powder is placed in a press that generates extremely high pressure and temperature, reproducing conditions found deep in the Earth’s mantle. Under these conditions, quantum centers form inside the nanodiamond.

To prevent the particles from fusing together, regular table salt is added. It melts during heating, creating a protective environment. After the process, the salt is simply removed with water, leaving a pure and luminous substance.

“We have accelerated the creation of quantum centers in nanodiamonds by more than a thousand times compared to standard procedures,” says Dr. Michal Julka, a postdoctoral researcher in Peter Siegler’s group and first author of the study. “Until now, diamond powder had to be irradiated with a beam of charged particles for two weeks and then annealed at high temperature. The result was less than one gram of usable material. We can now produce it in kilograms.”

Nanodiamonds are particles smaller than a virus that are used in advanced diagnostics to measure magnetic fields, charge, or temperature. They act as highly sensitive sensors thanks to the nitrogen vacancy (NV) center, which is a nitrogen atom located next to a carbon atom missing in the diamond lattice. The NV center is fluorescent, which means that when illuminated, it emits light. The intensity and timing of this light depends on changes in the surrounding environment, allowing nanodiamonds to detect even single molecules or measure the temperature inside cells.

A major contributor to the project is the American company MegaDiamond, which plans to launch industrial production of these nanosensors.

“Thanks to the new method, laboratories and companies around the world can obtain large quantities of high-quality nanodiamonds through NV centers, opening the door to new technologies – from microsensors for medical diagnostics to local molecular detectors based on principles such as magnetic resonance,” adds Dr. Siegler.